Display sha256sum on the package version details page

16 files changed, 398 insertions, 194 deletions

diff --git a/brep/mod-package-version-details.cxx b/brep/mod-package-version-details.cxx
index cbf9c86..992b829 100644
--- a/brep/mod-package-version-details.cxx
+++ b/brep/mod-package-version-details.cxx
@@ -161,7 +161,7 @@ handle (request& rq, response& rs)
           : P_DESCRIPTION (*d, options_->package_description (),
                            url (!full, id)));
 
-  assert (pkg->location);
+  assert (pkg->location && pkg->sha256sum);
 
   s << TABLE(CLASS="proplist", ID="version")
     <<   TBODY
@@ -175,6 +175,7 @@ handle (request& rq, response& rs)
     <<     TR_LOCATION (pkg->internal_repository.object_id (), root)
     <<     TR_DOWNLOAD (pkg->internal_repository.load ()->location.string () +
                         "/" + pkg->location->string ())
+    <<     TR_SHA256SUM (*pkg->sha256sum)
     <<   ~TBODY
     << ~TABLE
 
diff --git a/brep/package b/brep/package
index fa129f3..67f0e31 100644
--- a/brep/package
+++ b/brep/package
@@ -132,7 +132,7 @@ namespace brep
                              std::chrono::nanoseconds::period>::value,
     "The following timestamp ODB mapping is invalid");
 
-  // As it pointed out in butl/timestamp we will overflow in year 2262 but
+  // As it pointed out in butl/timestamp we will overflow in year 2262, but
   // by that time some larger basic type will be available for mapping.
   //
   #pragma db map type(timestamp) as(uint64_t)                 \
@@ -470,6 +470,7 @@ namespace brep
              dependencies_type,
              requirements_type,
              optional<path> location,
+             optional<string> sha256sum,
              shared_ptr<repository_type>);
 
     // Create external package object.
@@ -506,6 +507,10 @@ namespace brep
     //
     optional<path> location;
 
+    // Present only for internal packages.
+    //
+    optional<string> sha256sum;
+
     vector<lazy_shared_ptr<repository_type>> other_repositories;
 
     // Database mapping.
diff --git a/brep/package.cxx b/brep/package.cxx
index 1f93a56..d1bbe21 100644
--- a/brep/package.cxx
+++ b/brep/package.cxx
@@ -62,6 +62,7 @@ namespace brep
            dependencies_type dp,
            requirements_type rq,
            optional<path> lc,
+           optional<string> sh,
            shared_ptr<repository_type> rp)
       : id (move (nm), vr),
         version (move (vr)),
@@ -78,7 +79,8 @@ namespace brep
         dependencies (move (dp)),
         requirements (move (rq)),
         internal_repository (move (rp)),
-        location (move (lc))
+        location (move (lc)),
+        sha256sum (move (sh))
   {
     assert (internal_repository->internal);
   }
diff --git a/brep/package.xml b/brep/package.xml
index 6abbf1d..14598a5 100644
--- a/brep/package.xml
+++ b/brep/package.xml
@@ -87,6 +87,7 @@
       <column name="package_email_comment" type="TEXT" null="true"/>
       <column name="internal_repository" type="TEXT" null="true"/>
       <column name="location" type="TEXT" null="true"/>
+      <column name="sha256sum" type="TEXT" null="true"/>
       <column name="search_index" type="tsvector" null="true"/>
       <primary-key>
         <column name="name"/>
diff --git a/brep/page b/brep/page
index 4f97ef8..512c11a 100644
--- a/brep/page
+++ b/brep/page
@@ -293,6 +293,20 @@ namespace brep
     const string& url_;
   };
 
+  // Generates sha256sum element.
+  //
+  class TR_SHA256SUM
+  {
+  public:
+    TR_SHA256SUM (const string& s): sha256sum_ (s) {}
+
+    void
+    operator() (xml::serializer&) const;
+
+  private:
+    const string& sha256sum_;
+  };
+
   // Generates comment element.
   //
   class SPAN_COMMENT
diff --git a/brep/page.cxx b/brep/page.cxx
index 27e1b2a..689ee20 100644
--- a/brep/page.cxx
+++ b/brep/page.cxx
@@ -481,6 +481,17 @@ namespace brep
       << ~TR;
   }
 
+  // TR_SHA256SUM
+  //
+  void TR_SHA256SUM::
+  operator() (serializer& s) const
+  {
+    s << TR(CLASS="sha256")
+      <<   TH << "sha256" << ~TH
+      <<   TD << SPAN(CLASS="value") << sha256sum_ << ~SPAN << ~TD
+      << ~TR;
+  }
+
   // SPAN_COMMENT
   //
   void SPAN_COMMENT::
diff --git a/load/buildfile b/load/buildfile
index 6b72dae..333c091 100644
--- a/load/buildfile
+++ b/load/buildfile
@@ -15,6 +15,7 @@ exe{brep-load}:                   \
 ../brep/lib{brep} $libs
 
 cli.options += -I $src_root --include-with-brackets --include-prefix load \
---guard-prefix LOAD
+--guard-prefix LOAD --generate-specifier --page-usage print_ --ansi-color \
+--long-usage
 
 {hxx ixx cxx}{load-options}: cli{load}
diff --git a/load/load.cli b/load/load.cli
index 751d1bd..5c30c14 100644
--- a/load/load.cli
+++ b/load/load.cli
@@ -2,6 +2,7 @@
 // copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
+include <vector>;
 include <string>;
 include <cstdint>; // uint16_t
 
@@ -21,9 +22,9 @@ include <cstdint>; // uint16_t
    \h|DESCRIPTION|
 
    \cb{brep-load} reads the list of repositories from the specified
-   configuration <file>, fetches their manifest files, and loads the repository
-   and package information into the database, suitable for consumption by the
-   \cb{brep} web module.
+   configuration <file>, fetches their manifest files, and loads the
+   repository and package information into the database, suitable for
+   consumption by the \cb{brep} web module.
 
    Note that \cb{brep-load} expects the database schema to have already been
    created using \l{brep-migrate(1)}."
@@ -67,6 +68,36 @@ class options
     "Database port number. If not specified, the default port is used."
   }
 
+  std::string --pager // String to allow empty value.
+  {
+    "<path>",
+    "The pager program to be used to show long text. Commonly used pager
+     programs are \cb{less} and \cb{more}. You can also specify additional
+     options that should be passed to the pager program with
+     \cb{--pager-option}. If an empty string is specified as the pager
+     program, then no pager will be used. If the pager program is not
+     explicitly specified, then \cb{brep-load} will try to use \cb{less}. If
+     it is not available, then no pager will be used."
+  }
+
+  std::vector<std::string> --pager-option
+  {
+    "<opt>",
+    "Additional option to be passed to the pager program. See \cb{--pager}
+     for more information on the pager program. Repeat this option to
+     specify multiple pager options."
+  }
+
   bool --help {"Print usage information and exit."}
   bool --version {"Print version and exit."}
 };
+
+"\h|EXIT STATUS|
+
+\cb{0}      Successful termination.
+
+\cb{1}      \cb{brep-load} or \l{brep-migrate(1)} instance is running. Try
+            again.
+
+\cb{2}      Fatal error.
+"
diff --git a/load/load.cxx b/load/load.cxx
index b4dcd11..7556449 100644
--- a/load/load.cxx
+++ b/load/load.cxx
@@ -2,7 +2,6 @@
 // copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <sstream>
 #include <fstream>
 #include <iostream>
 #include <algorithm> // find(), find_if()
@@ -14,6 +13,7 @@
 
 #include <odb/pgsql/database.hxx>
 
+#include <butl/pager>
 #include <butl/filesystem>
 
 #include <bpkg/manifest-parser> // manifest_parsing
@@ -34,15 +34,12 @@ using namespace butl;
 using namespace bpkg;
 using namespace brep;
 
-static void
-usage (ostream& os)
-{
-  os << "Usage: brep-load [options] <file>" << endl
-     << "File lists internal repositories." << endl
-     << "Options:" << endl;
+// Operation failed, diagnostics has already been issued.
+//
+struct failed: std::exception {};
 
-  options::print_usage (os);
-}
+static const char* help_info (
+  "  info: run 'brep-load --help' for more information");
 
 static inline bool
 space (char c) noexcept
@@ -75,7 +72,10 @@ load_repositories (path p)
 
   ifstream ifs (p.string ());
   if (!ifs.is_open ())
-    throw ifstream::failure (p.string () + ": unable to open");
+  {
+    cerr << "error: unable to open " << p << " in read mode" << endl;
+    throw failed ();
+  }
 
   ifs.exceptions (ifstream::badbit);
 
@@ -108,11 +108,13 @@ load_repositories (path p)
       auto pb (i);  // Location begin.
       skip (false); // Find end of location.
 
-      auto bad_line ([&p, l, &pb, &b](const string& d) {
-          ostringstream os;
-          os << p << ':' << l << ':' << pb - b + 1 << ": error: " << d;
-          throw runtime_error (os.str ());
-        });
+      auto bad_line = [&p, l, &pb, &b](const string& d)
+      {
+        cerr << p << ':' << l << ':' << pb - b + 1 << ": error: " << d
+             << endl;
+
+        throw failed ();
+      };
 
       repository_location location;
 
@@ -186,7 +188,8 @@ load_repositories (path p)
   }
   catch (const ifstream::failure&)
   {
-    throw ifstream::failure (p.string () + ": io failure");
+    cerr << "error: unable to read " << p << endl;
+    throw failed ();
   }
 
   return repos;
@@ -208,7 +211,8 @@ changed (const internal_repositories& repos, database& db)
       db.find<repository> (r.location.canonical_name ()));
 
     if (pr == nullptr || r.location.string () != pr->location.string () ||
-        r.display_name != pr->display_name || r.local_path != pr->local_path ||
+        r.display_name != pr->display_name ||
+        r.local_path != pr->local_path ||
         file_mtime (r.packages_path ()) != pr->packages_timestamp ||
         file_mtime (r.repositories_path ()) != pr->repositories_timestamp ||
         !pr->internal)
@@ -224,8 +228,8 @@ changed (const internal_repositories& repos, database& db)
   //
   return
     !db.query<repository> (
-      query::internal && !query::name.in_range (names.begin (), names.end ())).
-    empty ();
+      query::internal &&
+      !query::name.in_range (names.begin (), names.end ())).empty ();
 }
 
 static timestamp
@@ -233,7 +237,10 @@ manifest_stream (const path& p, ifstream& f)
 {
   f.open (p.string ());
   if (!f.is_open ())
-    throw ifstream::failure (p.string () + ": unable to open");
+  {
+    cerr << "error: unable to open " << p << " in read mode" << endl;
+    throw failed ();
+  }
 
   f.exceptions (ifstream::badbit | ifstream::failbit);
   return file_mtime (p);
@@ -268,7 +275,13 @@ load_packages (const shared_ptr<repository>& rp, database& db)
 
   for (auto& pm: pkm)
   {
-    shared_ptr<package> p (db.find<package> (package_id (pm.name, pm.version)));
+    shared_ptr<package> p (
+      db.find<package> (package_id (pm.name, pm.version)));
+
+    // sha256sum should always be present if the package manifest comes from
+    // the 'packages' file.
+    //
+    assert (pm.sha256sum);
 
     if (p == nullptr)
     {
@@ -338,6 +351,7 @@ load_packages (const shared_ptr<repository>& rp, database& db)
           move (ds),
           move (pm.requirements),
           move (pm.location),
+          move (pm.sha256sum),
           rp);
       }
       else
@@ -349,16 +363,19 @@ load_packages (const shared_ptr<repository>& rp, database& db)
     }
     else
     {
-      // @@ Need to ensure that the same packages coming from different
-      //    repositories are equal. Probably will invent hashsum at some point
-      //    for this purpose.
-      //
-
       // As soon as internal repositories get loaded first, the internal
       // package can duplicate an internal package only.
       //
       assert (!rp->internal || p->internal ());
 
+      if (rp->internal && pm.sha256sum != p->sha256sum)
+        cerr << "warning: sha256sum mismatch for package " << p->id.name
+             << " " << p->version << endl
+             << "  info: " << p->internal_repository.load ()->location
+             << " has " << *p->sha256sum << endl
+             << "  info: " << rp->location << " has " << *pm.sha256sum
+             << endl;
+
       p->other_repositories.push_back (rp);
       db.update (p);
     }
@@ -402,7 +419,8 @@ load_repositories (const shared_ptr<repository>& rp, database& db)
 
   for (auto& rm: rpm)
   {
-    if (rm.effective_role () == repository_role::prerequisite && !rp->internal)
+    if (rm.effective_role () == repository_role::prerequisite &&
+        !rp->internal)
       continue; // Ignore the external repository prerequisite entry.
 
     if (rm.effective_role () == repository_role::base)
@@ -449,12 +467,12 @@ load_repositories (const shared_ptr<repository>& rp, database& db)
     auto bad_location (
       [&rp, &rm]()
       {
-        ostringstream o;
-        o << "invalid location '" << rm.location.string ()
-          << "' of the prerequisite repository for internal "
-          "repository '" << rp->location.string () << "'";
+        cerr << "error: invalid prerequisite repository location "
+             << rm.location << endl
+             << "  info: base (internal) repository location is "
+             << rp->location << endl;
 
-        throw runtime_error (o.str ());
+        throw failed ();
       });
 
     try
@@ -508,12 +526,12 @@ load_repositories (const shared_ptr<repository>& rp, database& db)
       }
       catch (const invalid_path&)
       {
-        ostringstream o;
-        o << "can't normalize local path'" << lp.string ()
-          << "' of the prerequisite repository for internal "
-          "repository '" << rp->location.string () << "'";
+        cerr << "error: can't normalize prerequisite repository local path '"
+             << lp << "'" << endl
+             << "  info: base (internal) repository location is "
+             << rp->location << endl;
 
-        throw runtime_error (o.str ());
+        throw failed ();
       }
     }
 
@@ -536,7 +554,8 @@ find (const lazy_shared_ptr<repository>& r,
   assert (r != nullptr);
 
   const auto& o (p.other_repositories);
-  if (r == p.internal_repository || find (o.begin (), o.end (), r) != o.end ())
+  if (r == p.internal_repository ||
+      find (o.begin (), o.end (), r) != o.end ())
     return true;
 
   auto rp (r.load ());
@@ -629,17 +648,18 @@ resolve_dependencies (package& p, database& db)
 
       if (d.package.object_id ().version.empty ())
       {
-        ostringstream o;
-        o << "can't resolve dependency " << d << " of the package "
-          << p.id.name << " " << p.version.string ()
-          << " (" << p.internal_repository.load ()->name << ")";
+        cerr << "error: can't resolve dependency " << d << " of the package "
+             << p.id.name << " " << p.version << endl
+             << "  info: repository "
+             << p.internal_repository.load ()->location
+             << " appears to be broken" << endl;
 
         // Practically it is enough to resolve at least one dependency
         // alternative to build a package. Meanwhile here we consider an error
         // specifying in the manifest file an alternative which can't be
         // resolved.
         //
-        throw runtime_error (o.str ());
+        throw failed ();
       }
     }
   }
@@ -650,14 +670,15 @@ resolve_dependencies (package& p, database& db)
 using package_ids = vector<package_id>;
 
 // Ensure the package dependency chain do not contain the package id. Throw
-// runtime_error otherwise. Continue the chain with the package id and call
-// itself recursively for each prerequisite of the package. Should be called
-// once per internal package.
+// failed otherwise. Continue the chain with the package id and call itself
+// recursively for each prerequisite of the package. Should be called once per
+// internal package.
 //
 // @@ This should probably be eventually moved to bpkg.
 //
 static void
-detect_dependency_cycle (const package_id& id, package_ids& chain, database& db)
+detect_dependency_cycle (
+  const package_id& id, package_ids& chain, database& db)
 {
   // Package of one version depending on the same package of another version
   // is something obscure. So the comparison is made up to a package name.
@@ -667,11 +688,10 @@ detect_dependency_cycle (const package_id& id, package_ids& chain, database& db)
 
   if (i != chain.end ())
   {
-    ostringstream o;
-    o << "package dependency cycle: ";
+    cerr << "error: package dependency cycle: ";
 
     auto prn (
-      [&o, &db](const package_id& id)
+      [&db](const package_id& id)
       {
         shared_ptr<package> p (db.load<package> (id));
         assert (p->internal () || !p->other_repositories.empty ());
@@ -681,17 +701,18 @@ detect_dependency_cycle (const package_id& id, package_ids& chain, database& db)
           ? p->internal_repository.load ()
           : p->other_repositories[0].load ());
 
-        o << id.name << " " << p->version.string () << " (" << r->name << ")";
+        cerr << id.name << " " << p->version << " (" << r->name << ")";
       });
 
     for (; i != chain.end (); ++i)
     {
       prn (*i);
-      o << " -> ";
+      cerr << " -> ";
     }
 
     prn (id);
-    throw runtime_error (o.str ());
+    cerr << endl;
+    throw failed ();
   }
 
   chain.push_back (id);
@@ -731,22 +752,30 @@ try
   //
   if (ops.help ())
   {
-    usage (cout);
-    return 0;
+    pager p ("brep-load help",
+             false,
+             ops.pager_specified () ? &ops.pager () : nullptr,
+             &ops.pager_option ());
+
+    print_usage (p.stream ());
+
+    // If the pager failed, assume it has issued some diagnostics.
+    //
+    return p.wait () ? 0 : 2;
   }
 
   if (argc < 2)
   {
-    cerr << "<file> argument not provided" << endl;
-    usage (cerr);
-    return 1;
+    cerr << "error: configuration file path argument expected" << endl
+         << help_info << endl;
+    return 2;
   }
 
   if (argc > 2)
   {
-    cerr << "unexpected argument encountered" << endl;
-    usage (cerr);
-    return 1;
+    cerr << "error: unexpected argument encountered" << endl
+         << help_info << endl;
+    return 2;
   }
 
   odb::pgsql::database db (ops.db_user (),
@@ -766,8 +795,9 @@ try
   //
   if (schema_catalog::current_version (db) != db.schema_version ())
   {
-    cerr << "database schema differs from the current one" << endl;
-    return 1;
+    cerr << "error: database schema differs from the current one" << endl
+         << "  info: use brep-migrate to migrate the database" << endl;
+    return 2;
   }
 
   // Load the description of all the internal repositories from the
@@ -827,22 +857,26 @@ try
   }
 
   t.commit ();
+  return 0;
 }
 catch (const database_locked&)
 {
   cerr << "brep-load or brep-migrate instance is running" << endl;
-  return 2;
+  return 1;
 }
 catch (const cli::exception& e)
 {
-  cerr << e << endl;
-  usage (cerr);
-  return 1;
+  cerr << "error: " << e << endl << help_info << endl;
+  return 2;
+}
+catch (const failed&)
+{
+  return 2; // Diagnostics has already been issued.
 }
 // Fully qualified to avoid ambiguity with odb exception.
 //
 catch (const std::exception& e)
 {
-  cerr << e.what () << endl;
-  return 1;
+  cerr << "error: " << e.what () << endl;
+  return 2;
 }
diff --git a/migrate/buildfile b/migrate/buildfile
index cd0b9c8..1722fea 100644
--- a/migrate/buildfile
+++ b/migrate/buildfile
@@ -2,6 +2,7 @@
 # copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
+import libs += libbutl%lib{butl}
 import libs += libodb-pgsql%lib{odb-pgsql}
 import libs += libodb%lib{odb}
 
@@ -13,6 +14,7 @@ exe{brep-migrate}:                   \
 ../brep/lib{brep} $libs
 
 cli.options += -I $src_root --include-with-brackets --include-prefix migrate \
---guard-prefix MIGRATE
+--guard-prefix MIGRATE --generate-specifier --page-usage print_ --ansi-color \
+--long-usage
 
 {hxx ixx cxx}{migrate-options}: cli{migrate}
diff --git a/migrate/migrate.cli b/migrate/migrate.cli
index 35d082f..dcbf667 100644
--- a/migrate/migrate.cli
+++ b/migrate/migrate.cli
@@ -2,6 +2,7 @@
 // copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
+include <vector>;
 include <string>;
 include <cstdint>; // uint16_t
 
@@ -85,6 +86,36 @@ class options
     "Database port number. If not specified, the default port is used."
   }
 
+  std::string --pager // String to allow empty value.
+  {
+    "<path>",
+    "The pager program to be used to show long text. Commonly used pager
+     programs are \cb{less} and \cb{more}. You can also specify additional
+     options that should be passed to the pager program with
+     \cb{--pager-option}. If an empty string is specified as the pager
+     program, then no pager will be used. If the pager program is not
+     explicitly specified, then \cb{brep-migrate} will try to use \cb{less}.
+     If it is not available, then no pager will be used."
+  }
+
+  std::vector<std::string> --pager-option
+  {
+    "<opt>",
+    "Additional option to be passed to the pager program. See \cb{--pager}
+     for more information on the pager program. Repeat this option to
+     specify multiple pager options."
+  }
+
   bool --help {"Print usage information and exit."}
   bool --version {"Print version and exit."}
 };
+
+"\h|EXIT STATUS|
+
+\cb{0}      Successful termination.
+
+\cb{1}      \cb{brep-migrate} or \l{brep-load(1)} instance is running. Try
+            again.
+
+\cb{2}      Fatal error.
+"
diff --git a/migrate/migrate.cxx b/migrate/migrate.cxx
index 702eba0..70ba54f 100644
--- a/migrate/migrate.cxx
+++ b/migrate/migrate.cxx
@@ -13,6 +13,8 @@
 
 #include <odb/pgsql/database.hxx>
 
+#include <butl/pager>
+
 #include <brep/types>
 #include <brep/utility>
 #include <brep/version>
@@ -25,6 +27,13 @@ using namespace std;
 using namespace odb::core;
 using namespace brep;
 
+// Operation failed, diagnostics has already been issued.
+//
+struct failed: std::exception {};
+
+static const char* help_info (
+  "  info: run 'brep-migrate --help' for more information");
+
 // Helper class that encapsulates both the ODB-generated schema and the
 // extra that comes from a .sql file (via xxd).
 //
@@ -108,19 +117,28 @@ schema (const char* s)
         if (strcasecmp (kw.c_str (), "FUNCTION") == 0)
         {
           if (!read_until ("$$") || !read_until ("$$"))
-            throw invalid_argument (
-              "function body must be defined using $$-quoted strings");
+          {
+            cerr << "error: function body must be defined using $$-quoted "
+              "strings" << endl;
+            throw failed ();
+          }
         }
         else if (strcasecmp (kw.c_str (), "TYPE") == 0)
         {
           // Fall through.
         }
         else
-          throw invalid_argument ("unexpected CREATE statement");
+        {
+          cerr << "error: unexpected CREATE statement" << endl;
+          throw failed ();
+        }
 
         if (!read_until (";\n"))
-          throw invalid_argument (
-            "expected ';\\n' at the end of CREATE statement");
+        {
+          cerr << "error: expected ';\\n' at the end of CREATE statement"
+               << endl;
+          throw failed ();
+        }
 
         assert (!statement.empty ());
         create_statements_.emplace_back (move (statement));
@@ -128,15 +146,21 @@ schema (const char* s)
       else if (strcasecmp (op.c_str (), "DROP") == 0)
       {
         if (!read_until (";\n"))
-          throw invalid_argument (
-            "expected ';\\n' at the end of DROP statement");
+        {
+          cerr << "error: expected ';\\n' at the end of DROP statement"
+               << endl;
+          throw failed ();
+        }
 
         assert (!statement.empty ());
         drop_statements_.emplace_back (move (statement));
       }
       else
-        throw invalid_argument (
-          "unexpected statement starting with '" + op + "'");
+      {
+        cerr << "error: unexpected statement starting with '" << op << "'"
+             << endl;
+        throw failed ();
+      }
     }
   }
 }
@@ -166,17 +190,6 @@ create (database& db) const
     db.execute (s);
 }
 
-// Utility functions
-//
-static void
-usage (ostream& os)
-{
-  os << "Usage: brep-migrate [options]" << endl
-     << "Options:" << endl;
-
-  options::print_usage (os);
-}
-
 // main() function
 //
 int
@@ -204,22 +217,30 @@ try
   //
   if (ops.help ())
   {
-    usage (cout);
-    return 0;
+    butl::pager p ("brep-migrate help",
+                   false,
+                   ops.pager_specified () ? &ops.pager () : nullptr,
+                   &ops.pager_option ());
+
+    print_usage (p.stream ());
+
+    // If the pager failed, assume it has issued some diagnostics.
+    //
+    return p.wait () ? 0 : 2;
   }
 
   if (argc > 1)
   {
-    cerr << "unexpected argument encountered" << endl;
-    usage (cerr);
-    return 1;
+    cerr << "error: unexpected argument encountered" << endl
+         << help_info << endl;
+    return 2;
   }
 
   if (ops.recreate () && ops.drop ())
   {
-    cerr << "inconsistent options specified" << endl;
-    usage (cerr);
-    return 1;
+    cerr << "error: inconsistent options specified" << endl
+         << help_info << endl;
+    return 2;
   }
 
   odb::pgsql::database db (ops.db_user (),
@@ -247,10 +268,16 @@ try
   if (schema_version > 0)
   {
     if (schema_version < schema_catalog::base_version (db))
-      throw runtime_error ("database schema is too old");
+    {
+      cerr << "error: database schema is too old" << endl;
+      throw failed ();
+    }
 
     if (schema_version > schema_catalog::current_version (db))
-      throw runtime_error ("database schema is too new");
+    {
+      cerr << "error: database schema is too new" << endl;
+      throw failed ();
+    }
   }
 
   bool drop (ops.drop ());
@@ -264,7 +291,12 @@ try
   //
   if ((create || drop) && schema_version != 0 &&
       schema_version != schema_catalog::current_version (db))
-    throw runtime_error ("database schema requires migration");
+  {
+    cerr << "error: database schema requires migration" << endl
+         << "  info: either migrate the database first or drop the entire "
+            "database using, for example, psql" << endl;
+    throw failed ();
+  }
 
   transaction t (db.begin ());
 
@@ -292,22 +324,26 @@ try
   }
 
   t.commit ();
+  return 0;
 }
 catch (const database_locked&)
 {
   cerr << "brep-migrate or brep-load instance is running" << endl;
-  return 2;
+  return 1;
 }
 catch (const cli::exception& e)
 {
-  cerr << e << endl;
-  usage (cerr);
-  return 1;
+  cerr << "error: " << e << endl << help_info << endl;
+  return 2;
+}
+catch (const failed&)
+{
+  return 2; // Diagnostics has already been issued.
 }
 // Fully qualified to avoid ambiguity with odb exception.
 //
 catch (const std::exception& e)
 {
-  cerr << e.what () << endl;
-  return 1;
+  cerr << "error: " << e.what () << endl;
+  return 2;
 }
diff --git a/tests/load/1/math/packages b/tests/load/1/math/packages
index 9c8bfea..115e3f1 100644
--- a/tests/load/1/math/packages
+++ b/tests/load/1/math/packages
@@ -74,4 +74,4 @@ license: MIT
 url: http://www.example.com/foo/
 email: foo-users@example.com
 location: libfoo-1.0.tar.gz
-sha256sum: 45ccba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93
+sha256sum: 754cba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93
diff --git a/tests/load/1/misc/packages b/tests/load/1/misc/packages
index 9cffca5..f4f7f59 100644
--- a/tests/load/1/misc/packages
+++ b/tests/load/1/misc/packages
@@ -24,7 +24,7 @@ license: MIT
 url: http://www.example.com/foo/
 email: foo-users@example.com
 location: libfoo-1.0.tar.gz
-sha256sum: 71ccba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93
+sha256sum: 754cba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93
 :
 name: libfoo
 version: 0.1
@@ -42,7 +42,7 @@ license: MIT
 url: http://www.example.com/foo/
 email: foo-users@example.com
 location: libfoo-1.2.4+1.tar.gz
-sha256sum: 73ccba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93
+sha256sum: 35ccba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93
 :
 name: libfoo
 version: 1.2.4+2
diff --git a/tests/load/driver.cxx b/tests/load/driver.cxx
index 41e4623..a9b9823 100644
--- a/tests/load/driver.cxx
+++ b/tests/load/driver.cxx
@@ -39,11 +39,11 @@ static bool
 check_external (const package& p)
 {
   return p.summary.empty () && p.tags.empty () && !p.description &&
-    p.url.empty () && !p.package_url && p.email.empty () && !p.package_email &&
-    !p.internal () && p.other_repositories.size () > 0 &&
+    p.url.empty () && !p.package_url && p.email.empty () &&
+    !p.package_email && !p.internal () && p.other_repositories.size () > 0 &&
     p.priority == priority () && p.changes.empty () &&
     p.license_alternatives.empty () && p.dependencies.empty () &&
-    p.requirements.empty ();
+    p.requirements.empty () && !p.sha256sum;
 }
 
 int
@@ -122,27 +122,6 @@ main (int argc, char* argv[])
       assert (sr->repositories_timestamp ==
               file_mtime (dir_path (sr->local_path) / path ("repositories")));
       assert (sr->internal);
-
-      shared_ptr<package> fpv1 (
-        db.load<package> (package_id ("libfoo", version ("1.0"))));
-      assert (check_location (fpv1));
-
-      shared_ptr<package> fpv2 (
-        db.load<package> (package_id ("libfoo", version ("1.2.2"))));
-      assert (check_location (fpv2));
-
-      shared_ptr<package> fpv2a (
-        db.load<package> (package_id ("libfoo", version ("1.2.2-alpha.1"))));
-      assert (check_location (fpv2a));
-
-      shared_ptr<package> fpv3 (
-        db.load<package> (package_id ("libfoo", version ("1.2.3+4"))));
-      assert (check_location (fpv3));
-
-      shared_ptr<package> fpv4 (
-        db.load<package> (package_id ("libfoo", version ("1.2.4"))));
-      assert (check_location (fpv4));
-
       assert (sr->complements.empty ());
       assert (sr->prerequisites.size () == 2);
       assert (sr->prerequisites[0].load () == cr);
@@ -152,6 +131,9 @@ main (int argc, char* argv[])
       //
       // libfoo-1.0
       //
+      shared_ptr<package> fpv1 (
+        db.load<package> (package_id ("libfoo", version ("1.0"))));
+
       assert (fpv1->summary == "The Foo Library");
       assert (fpv1->tags.empty ());
       assert (!fpv1->description);
@@ -175,8 +157,16 @@ main (int argc, char* argv[])
       assert (fpv1->dependencies.empty ());
       assert (fpv1->requirements.empty ());
 
+      assert (check_location (fpv1));
+
+      assert (fpv1->sha256sum && *fpv1->sha256sum ==
+        "754cba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93");
+
       // libfoo-1.2.2
       //
+      shared_ptr<package> fpv2 (
+        db.load<package> (package_id ("libfoo", version ("1.2.2"))));
+
       assert (fpv2->summary == "The Foo library");
       assert (fpv2->tags == strings ({"c++", "foo"}));
       assert (!fpv2->description);
@@ -202,7 +192,8 @@ main (int argc, char* argv[])
         [&db](const char* n,
               const optional<dependency_constraint>& c) -> dependency
         {
-          return {lazy_shared_ptr<package> (db, package_id (n, version ())), c};
+          return {
+            lazy_shared_ptr<package> (db, package_id (n, version ())), c};
         });
 
       assert (fpv2->dependencies[0][0] ==
@@ -219,8 +210,16 @@ main (int argc, char* argv[])
                   dependency_constraint (
                     version ("1~1.2"), false, version ("1~1.2"), false))));
 
+      assert (check_location (fpv2));
+
+      assert (fpv2->sha256sum && *fpv2->sha256sum ==
+        "751cba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93");
+
       // libfoo-1.2.2-alpha.1
       //
+      shared_ptr<package> fpv2a (
+        db.load<package> (package_id ("libfoo", version ("1.2.2-alpha.1"))));
+
       assert (fpv2a->summary == "The Foo library");
       assert (fpv2a->tags == strings ({"c++", "foo"}));
       assert (!fpv2a->description);
@@ -280,8 +279,16 @@ main (int argc, char* argv[])
 
       assert (fpv2a->requirements.empty ());
 
+      assert (check_location (fpv2a));
+
+      assert (fpv2a->sha256sum && *fpv2a->sha256sum ==
+        "752cba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93");
+
       // libfoo-1.2.3-4
       //
+      shared_ptr<package> fpv3 (
+        db.load<package> (package_id ("libfoo", version ("1.2.3+4"))));
+
       assert (fpv3->summary == "The Foo library");
       assert (fpv3->tags == strings ({"c++", "foo"}));
       assert (!fpv3->description);
@@ -309,8 +316,16 @@ main (int argc, char* argv[])
                   dependency_constraint (
                     version ("2.0.0"), false, nullopt, true))));
 
+      assert (check_location (fpv3));
+
+      assert (fpv3->sha256sum && *fpv3->sha256sum ==
+        "750cba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93");
+
       // libfoo-1.2.4
       //
+      shared_ptr<package> fpv4 (
+        db.load<package> (package_id ("libfoo", version ("1.2.4"))));
+
       assert (fpv4->summary == "The Foo Library");
       assert (fpv4->tags == strings ({"c++", "foo"}));
       assert (*fpv4->description == "Very good foo library.");
@@ -339,6 +354,11 @@ main (int argc, char* argv[])
                   dependency_constraint (
                     version ("2.0.0"), false, nullopt, true))));
 
+      assert (check_location (fpv4));
+
+      assert (fpv4->sha256sum && *fpv4->sha256sum ==
+        "753cba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93");
+
       // Verify 'math' repository.
       //
       assert (mr->location.canonical_name () == "cppget.org/math");
@@ -362,24 +382,15 @@ main (int argc, char* argv[])
               file_mtime (dir_path (mr->local_path) / path ("repositories")));
       assert (mr->internal);
 
-      shared_ptr<package> epv (
-        db.load<package> (package_id ("libexp", version ("1~1.2+1"))));
-      assert (check_location (epv));
-
-      shared_ptr<package> fpv5 (
-        db.load<package> (package_id ("libfoo", version ("1.2.4+1"))));
-      assert (check_location (fpv5));
-
-      shared_ptr<package> xpv (
-        db.load<package> (package_id ("libstudxml", version ("1.0.0+1"))));
-      assert (check_location (xpv));
-
       assert (mr->complements.empty ());
       assert (mr->prerequisites.size () == 1);
       assert (mr->prerequisites[0].load () == cr);
 
       // Verify libstudxml package version.
       //
+      shared_ptr<package> xpv (
+        db.load<package> (package_id ("libstudxml", version ("1.0.0+1"))));
+
       assert (xpv->summary == "Modern C++ XML API");
       assert (xpv->tags == strings ({"c++", "xml", "parser", "serializer",
               "pull", "streaming", "modern"}));
@@ -417,18 +428,26 @@ main (int argc, char* argv[])
 
       assert (xpv->requirements.empty ());
 
+      assert (check_location (xpv));
+
+      assert (xpv->sha256sum && *xpv->sha256sum ==
+        "05ccba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93");
+
       // Verify libfoo package versions.
       //
       // libfoo-1.2.4-1
       //
+      shared_ptr<package> fpv5 (
+        db.load<package> (package_id ("libfoo", version ("1.2.4+1"))));
+
       assert (fpv5->summary == "The Foo Math Library");
       assert (fpv5->tags == strings ({"c++", "foo", "math"}));
       assert (*fpv5->description ==
-              "A modern C++ library with easy to use linear algebra and lot of "
-              "optimization\ntools.\n\nThere are over 100 functions in total "
-              "with an extensive test suite. The API is\nsimilar to MATLAB."
-              "\n\nUseful for conversion of research code into production "
-              "environments.");
+              "A modern C++ library with easy to use linear algebra and lot "
+              "of optimization\ntools.\n\nThere are over 100 functions in "
+              "total with an extensive test suite. The API is\nsimilar to "
+              "MATLAB.\n\nUseful for conversion of research code into "
+              "production environments.");
       assert (fpv5->url == "http://www.example.com/foo/");
       assert (fpv5->package_url &&
               *fpv5->package_url == "http://www.example.com/foo/pack");
@@ -518,10 +537,18 @@ main (int argc, char* argv[])
       assert (fpvr5[3].conditional);
       assert (fpvr5[3].comment == "Only if using VC++ on Windows.");
 
+      assert (check_location (fpv5));
+
+      assert (fpv5->sha256sum && *fpv5->sha256sum ==
+        "35ccba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93");
+
       // Verify libexp package version.
       //
       // libexp-1+1.2
       //
+      shared_ptr<package> epv (
+        db.load<package> (package_id ("libexp", version ("1~1.2+1"))));
+
       assert (epv->summary == "The exponent");
       assert (epv->tags == strings ({"c++", "exponent"}));
       assert (epv->description && *epv->description ==
@@ -546,6 +573,11 @@ main (int argc, char* argv[])
 
       assert (epv->requirements.empty ());
 
+      assert (check_location (epv));
+
+      assert (epv->sha256sum && *epv->sha256sum ==
+        "15ccba3da34dd0296866027a26b6bacf08cacc80f54516d3b8d8eeccbe31ab93");
+
       // Verify 'misc' repository.
       //
       assert (cr->location.canonical_name () == "cppget.org/misc");
@@ -566,19 +598,6 @@ main (int argc, char* argv[])
       assert (cr->repositories_timestamp ==
               file_mtime (dir_path (cr->local_path) / path ("repositories")));
       assert (!cr->internal);
-
-      shared_ptr<package> bpv (
-        db.load<package> (package_id ("libbar", version ("2.4.0+3"))));
-      assert (check_location (bpv));
-
-      shared_ptr<package> fpv0 (
-        db.load<package> (package_id ("libfoo", version ("0.1"))));
-      assert (check_location (fpv0));
-
-      shared_ptr<package> fpv6 (
-        db.load<package> (package_id ("libfoo", version ("1.2.4+2"))));
-      assert (check_location (fpv6));
-
       assert (cr->prerequisites.empty ());
       assert (cr->complements.size () == 1);
       assert (cr->complements[0].load () == tr);
@@ -587,23 +606,35 @@ main (int argc, char* argv[])
       //
       // libbar-2.4.0+3
       //
+      shared_ptr<package> bpv (
+        db.load<package> (package_id ("libbar", version ("2.4.0+3"))));
+
       assert (check_external (*bpv));
       assert (bpv->other_repositories.size () == 1);
       assert (bpv->other_repositories[0].load () == cr);
+      assert (check_location (bpv));
 
       // Verify libfoo package versions.
       //
       // libfoo-0.1
       //
+      shared_ptr<package> fpv0 (
+        db.load<package> (package_id ("libfoo", version ("0.1"))));
+
       assert (check_external (*fpv0));
       assert (fpv0->other_repositories.size () == 1);
       assert (fpv0->other_repositories[0].load () == cr);
+      assert (check_location (fpv0));
 
       // libfoo-1.2.4-2
       //
+      shared_ptr<package> fpv6 (
+        db.load<package> (package_id ("libfoo", version ("1.2.4+2"))));
+
       assert (check_external (*fpv6));
       assert (fpv6->other_repositories.size () == 1);
       assert (fpv6->other_repositories[0].load () == cr);
+      assert (check_location (fpv6));
 
       // Verify 'testing' repository.
       //
@@ -625,15 +656,6 @@ main (int argc, char* argv[])
       assert (tr->repositories_timestamp ==
               file_mtime (dir_path (tr->local_path) / path ("repositories")));
       assert (!tr->internal);
-
-      shared_ptr<package> mpv0 (
-        db.load<package> (package_id ("libmisc", version ("2.4.0"))));
-      assert (check_location (mpv0));
-
-      shared_ptr<package> mpv1 (
-        db.load<package> (package_id ("libmisc", version ("2.3.0+1"))));
-      assert (check_location (mpv1));
-
       assert (tr->prerequisites.empty ());
       assert (tr->complements.size () == 1);
       assert (tr->complements[0].load () == gr);
@@ -642,15 +664,23 @@ main (int argc, char* argv[])
       //
       // libmisc-2.4.0
       //
+      shared_ptr<package> mpv0 (
+        db.load<package> (package_id ("libmisc", version ("2.4.0"))));
+
       assert (check_external (*mpv0));
       assert (mpv0->other_repositories.size () == 1);
       assert (mpv0->other_repositories[0].load () == tr);
+      assert (check_location (mpv0));
 
       // libmisc-2.3.0+1
       //
+      shared_ptr<package> mpv1 (
+        db.load<package> (package_id ("libmisc", version ("2.3.0+1"))));
+
       assert (check_external (*mpv1));
       assert (mpv1->other_repositories.size () == 1);
       assert (mpv1->other_repositories[0].load () == tr);
+      assert (check_location (mpv1));
 
       // Verify 'staging' repository.
       //
@@ -672,19 +702,6 @@ main (int argc, char* argv[])
       assert (gr->repositories_timestamp ==
               file_mtime (dir_path (gr->local_path) / path ("repositories")));
       assert (!gr->internal);
-
-      shared_ptr<package> tpv (
-        db.load<package> (package_id ("libexpat", version ("5.1"))));
-      assert (check_location (tpv));
-
-      shared_ptr<package> gpv (
-        db.load<package> (package_id ("libgenx", version ("1.0"))));
-      assert (check_location (gpv));
-
-      shared_ptr<package> mpv2 (
-        db.load<package> (package_id ("libmisc", version ("1.0"))));
-      assert (check_location (mpv2));
-
       assert (gr->prerequisites.empty ());
       assert (gr->complements.empty ());
 
@@ -692,25 +709,37 @@ main (int argc, char* argv[])
       //
       // libexpat-5.1
       //
+      shared_ptr<package> tpv (
+        db.load<package> (package_id ("libexpat", version ("5.1"))));
+
       assert (check_external (*tpv));
       assert (tpv->other_repositories.size () == 1);
       assert (tpv->other_repositories[0].load () == gr);
+      assert (check_location (tpv));
 
       // Verify libgenx package version.
       //
       // libgenx-1.0
       //
+      shared_ptr<package> gpv (
+        db.load<package> (package_id ("libgenx", version ("1.0"))));
+
       assert (check_external (*gpv));
       assert (gpv->other_repositories.size () == 1);
       assert (gpv->other_repositories[0].load () == gr);
+      assert (check_location (gpv));
 
       // Verify libmisc package version.
       //
       // libmisc-1.0
       //
+      shared_ptr<package> mpv2 (
+        db.load<package> (package_id ("libmisc", version ("1.0"))));
+
       assert (check_external (*mpv2));
       assert (mpv2->other_repositories.size () == 1);
       assert (mpv2->other_repositories[0].load () == gr);
+      assert (check_location (mpv2));
 
       // Change package summary, update the object persistent state, rerun
       // loader and ensure the model were not rebuilt.
diff --git a/www/package-version-details-body.css b/www/package-version-details-body.css
index 8af54bc..2b16668 100644
--- a/www/package-version-details-body.css
+++ b/www/package-version-details-body.css
@@ -103,6 +103,12 @@ h1, h2, h3
   font-size: 0.94em;
 }
 
+#version tr.sha256 td .value
+{
+  /* Increase the chances of 64-char value not to be truncated. */
+  font-size: 0.9em;
+}
+
 /*
  * Package details table.
  */