Prepare for supporting multiple dependencies in dependency alternative

7 files changed, 340 insertions, 89 deletions

diff --git a/libbrep/package.hxx b/libbrep/package.hxx
index 0ce8553..1927298 100644
--- a/libbrep/package.hxx
+++ b/libbrep/package.hxx
@@ -20,7 +20,7 @@
 //
 #define LIBBREP_PACKAGE_SCHEMA_VERSION_BASE 21
 
-#pragma db model version(LIBBREP_PACKAGE_SCHEMA_VERSION_BASE, 21, closed)
+#pragma db model version(LIBBREP_PACKAGE_SCHEMA_VERSION_BASE, 22, closed)
 
 namespace brep
 {
@@ -156,7 +156,17 @@ namespace brep
   operator!= (const dependency&, const dependency&);
 
   #pragma db value
-  class dependency_alternatives: public vector<dependency>
+  class dependency_alternative: public small_vector<dependency, 1>
+  {
+  public:
+    optional<string> enable;
+
+    dependency_alternative () = default;
+    dependency_alternative (optional<string> e): enable (move (e)) {}
+  };
+
+  #pragma db value
+  class dependency_alternatives: public small_vector<dependency_alternative, 1>
   {
   public:
     bool conditional;
@@ -183,7 +193,7 @@ namespace brep
                      test_dependency_type t,
                      bool b,
                      optional<version_constraint> c)
-        : dependency {std::move (n), std::move (c), nullptr /* package */},
+        : dependency {move (n), move (c), nullptr /* package */},
           type (t),
           buildtime (b)
     {
@@ -551,20 +561,48 @@ namespace brep
 
     // dependencies
     //
-    using _dependency_key = odb::nested_key<dependency_alternatives>;
+    // Note that this is a 2-level nested container which is mapped to three
+    // container tables each containing data of each dimension.
+
+    // Container of the dependency_alternatives values.
+    //
+    #pragma db member(dependencies) id_column("") value_column("")
+
+    // Container of the dependency_alternative values.
+    //
+    using _dependency_alternative_key =
+      odb::nested_key<dependency_alternatives>;
+
     using _dependency_alternatives_type =
-               std::map<_dependency_key, dependency>;
+      std::map<_dependency_alternative_key, dependency_alternative>;
 
-    #pragma db value(_dependency_key)
-    #pragma db member(_dependency_key::outer) column("dependency_index")
-    #pragma db member(_dependency_key::inner) column("index")
+    #pragma db value(_dependency_alternative_key)
+    #pragma db member(_dependency_alternative_key::outer) column("dependency_index")
+    #pragma db member(_dependency_alternative_key::inner) column("index")
 
-    #pragma db member(dependencies) id_column("") value_column("")
     #pragma db member(dependency_alternatives)                \
       virtual(_dependency_alternatives_type)                  \
       after(dependencies)                                     \
       get(odb::nested_get (this.dependencies))                \
       set(odb::nested_set (this.dependencies, std::move (?))) \
+      id_column("") key_column("") value_column("")
+
+    // Container of the dependency values.
+    //
+    using _dependency_key = odb::nested2_key<dependency_alternatives>;
+    using _dependency_alternative_dependencies_type =
+      std::map<_dependency_key, dependency>;
+
+    #pragma db value(_dependency_key)
+    #pragma db member(_dependency_key::outer)  column("dependency_index")
+    #pragma db member(_dependency_key::middle) column("alternative_index")
+    #pragma db member(_dependency_key::inner)  column("index")
+
+    #pragma db member(dependency_alternative_dependencies)     \
+      virtual(_dependency_alternative_dependencies_type)       \
+      after(dependency_alternatives)                           \
+      get(odb::nested2_get (this.dependencies))                \
+      set(odb::nested2_set (this.dependencies, std::move (?))) \
       id_column("") key_column("") value_column("dep_")
 
     // requirements
diff --git a/libbrep/package.xml b/libbrep/package.xml
index 69f5731..9e162ed 100644
--- a/libbrep/package.xml
+++ b/libbrep/package.xml
@@ -1,4 +1,117 @@
 <changelog xmlns="http://www.codesynthesis.com/xmlns/odb/changelog" database="pgsql" schema-name="package" version="1">
+  <changeset version="22">
+    <alter-table name="package_dependency_alternatives">
+      <add-column name="enable" type="TEXT" null="true"/>
+      <drop-foreign-key name="dep_package_tenant_fk"/>
+      <drop-foreign-key name="dep_package_fk"/>
+      <drop-column name="dep_name"/>
+      <drop-column name="dep_min_version_epoch"/>
+      <drop-column name="dep_min_version_canonical_upstream"/>
+      <drop-column name="dep_min_version_canonical_release"/>
+      <drop-column name="dep_min_version_revision"/>
+      <drop-column name="dep_min_version_upstream"/>
+      <drop-column name="dep_min_version_release"/>
+      <drop-column name="dep_max_version_epoch"/>
+      <drop-column name="dep_max_version_canonical_upstream"/>
+      <drop-column name="dep_max_version_canonical_release"/>
+      <drop-column name="dep_max_version_revision"/>
+      <drop-column name="dep_max_version_upstream"/>
+      <drop-column name="dep_max_version_release"/>
+      <drop-column name="dep_min_open"/>
+      <drop-column name="dep_max_open"/>
+      <drop-column name="dep_package_tenant"/>
+      <drop-column name="dep_package_name"/>
+      <drop-column name="dep_package_version_epoch"/>
+      <drop-column name="dep_package_version_canonical_upstream"/>
+      <drop-column name="dep_package_version_canonical_release"/>
+      <drop-column name="dep_package_version_revision"/>
+    </alter-table>
+    <add-table name="package_dependency_alternative_dependencies" kind="container">
+      <column name="tenant" type="TEXT" null="false"/>
+      <column name="name" type="CITEXT" null="false"/>
+      <column name="version_epoch" type="INTEGER" null="false"/>
+      <column name="version_canonical_upstream" type="TEXT" null="false"/>
+      <column name="version_canonical_release" type="TEXT" null="false" options="COLLATE &quot;C&quot;"/>
+      <column name="version_revision" type="INTEGER" null="false"/>
+      <column name="dependency_index" type="BIGINT" null="false"/>
+      <column name="alternative_index" type="BIGINT" null="false"/>
+      <column name="index" type="BIGINT" null="false"/>
+      <column name="dep_name" type="CITEXT" null="false"/>
+      <column name="dep_min_version_epoch" type="INTEGER" null="true"/>
+      <column name="dep_min_version_canonical_upstream" type="TEXT" null="true"/>
+      <column name="dep_min_version_canonical_release" type="TEXT" null="true"/>
+      <column name="dep_min_version_revision" type="INTEGER" null="true"/>
+      <column name="dep_min_version_upstream" type="TEXT" null="true"/>
+      <column name="dep_min_version_release" type="TEXT" null="true"/>
+      <column name="dep_max_version_epoch" type="INTEGER" null="true"/>
+      <column name="dep_max_version_canonical_upstream" type="TEXT" null="true"/>
+      <column name="dep_max_version_canonical_release" type="TEXT" null="true"/>
+      <column name="dep_max_version_revision" type="INTEGER" null="true"/>
+      <column name="dep_max_version_upstream" type="TEXT" null="true"/>
+      <column name="dep_max_version_release" type="TEXT" null="true"/>
+      <column name="dep_min_open" type="BOOLEAN" null="true"/>
+      <column name="dep_max_open" type="BOOLEAN" null="true"/>
+      <column name="dep_package_tenant" type="TEXT" null="true"/>
+      <column name="dep_package_name" type="CITEXT" null="true"/>
+      <column name="dep_package_version_epoch" type="INTEGER" null="true"/>
+      <column name="dep_package_version_canonical_upstream" type="TEXT" null="true"/>
+      <column name="dep_package_version_canonical_release" type="TEXT" null="true" options="COLLATE &quot;C&quot;"/>
+      <column name="dep_package_version_revision" type="INTEGER" null="true"/>
+      <foreign-key name="tenant_fk" deferrable="DEFERRED">
+        <column name="tenant"/>
+        <references table="tenant">
+          <column name="id"/>
+        </references>
+      </foreign-key>
+      <foreign-key name="object_id_fk" on-delete="CASCADE">
+        <column name="tenant"/>
+        <column name="name"/>
+        <column name="version_epoch"/>
+        <column name="version_canonical_upstream"/>
+        <column name="version_canonical_release"/>
+        <column name="version_revision"/>
+        <references table="package">
+          <column name="tenant"/>
+          <column name="name"/>
+          <column name="version_epoch"/>
+          <column name="version_canonical_upstream"/>
+          <column name="version_canonical_release"/>
+          <column name="version_revision"/>
+        </references>
+      </foreign-key>
+      <index name="package_dependency_alternative_dependencies_object_id_i">
+        <column name="tenant"/>
+        <column name="name"/>
+        <column name="version_epoch"/>
+        <column name="version_canonical_upstream"/>
+        <column name="version_canonical_release"/>
+        <column name="version_revision"/>
+      </index>
+      <foreign-key name="dep_package_tenant_fk" deferrable="DEFERRED">
+        <column name="dep_package_tenant"/>
+        <references table="tenant">
+          <column name="id"/>
+        </references>
+      </foreign-key>
+      <foreign-key name="dep_package_fk" deferrable="DEFERRED">
+        <column name="dep_package_tenant"/>
+        <column name="dep_package_name"/>
+        <column name="dep_package_version_epoch"/>
+        <column name="dep_package_version_canonical_upstream"/>
+        <column name="dep_package_version_canonical_release"/>
+        <column name="dep_package_version_revision"/>
+        <references table="package">
+          <column name="tenant"/>
+          <column name="name"/>
+          <column name="version_epoch"/>
+          <column name="version_canonical_upstream"/>
+          <column name="version_canonical_release"/>
+          <column name="version_revision"/>
+        </references>
+      </foreign-key>
+    </add-table>
+  </changeset>
+
   <model version="21">
     <table name="tenant" kind="object">
       <column name="id" type="TEXT" null="false"/>
diff --git a/load/load.cxx b/load/load.cxx
index 3408284..34e59a7 100644
--- a/load/load.cxx
+++ b/load/load.cxx
@@ -418,6 +418,8 @@ load_packages (const shared_ptr<repository>& rp,
   }
 
   using brep::dependency;
+  using brep::dependency_alternative;
+  using brep::dependency_alternatives;
 
   for (package_manifest& pm: pms)
   {
@@ -493,31 +495,46 @@ load_packages (const shared_ptr<repository>& rp,
           }
         }
 
-        dependencies ds;
+        dependencies tds;
 
-        for (auto& pda: pm.dependencies)
+        for (auto& das: pm.dependencies)
         {
           // Ignore special build2 and bpkg dependencies. We may not have
           // packages for them and also showing them for every package is
           // probably not very helpful.
           //
-          if (pda.buildtime && !pda.empty ())
+          if (das.buildtime && !das.empty ())
           {
-            const package_name& n (pda.front ().name);
+            const auto& da (das.front ());
+
+            assert (da.size () == 1); // @@ DEP
+
+            const package_name& n (da[0].name);
             if (n == "build2" || n == "bpkg")
               continue;
           }
 
-          ds.emplace_back (pda.conditional, pda.buildtime, move (pda.comment));
+          tds.emplace_back (das.conditional,
+                            das.buildtime,
+                            move (das.comment));
+
+          dependency_alternatives& tdas (tds.back ());
 
-          for (auto& pd: pda)
+          for (auto& da: das)
           {
-            // The package member will be assigned during dependency
-            // resolution procedure.
-            //
-            ds.back ().push_back (dependency {move (pd.name),
-                                              move (pd.constraint),
-                                              nullptr /* package */});
+            tdas.push_back (dependency_alternative (move (da.enable)));
+            dependency_alternative& tda (tdas.back ());
+
+            for (auto& d: da)
+            {
+              // The package member will be assigned during dependency
+              // resolution procedure.
+              //
+              tda.push_back (
+                dependency {move (d.name),
+                            move (d.constraint),
+                            nullptr /* package */});
+            }
           }
         }
 
@@ -560,7 +577,7 @@ load_packages (const shared_ptr<repository>& rp,
           move (pm.build_email),
           move (pm.build_warning_email),
           move (pm.build_error_email),
-          move (ds),
+          move (tds),
           move (pm.requirements),
           move (ts),
           move (pm.builds),
@@ -1022,6 +1039,7 @@ static void
 resolve_dependencies (package& p, database& db, bool ignore_unresolved)
 {
   using brep::dependency;
+  using brep::dependency_alternative;
   using brep::dependency_alternatives;
 
   // Resolve dependencies for internal packages only.
@@ -1130,17 +1148,20 @@ resolve_dependencies (package& p, database& db, bool ignore_unresolved)
     throw failed ();
   };
 
-  for (dependency_alternatives& da: p.dependencies)
+  for (dependency_alternatives& das: p.dependencies)
   {
-    for (dependency& d: da)
+    // 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, unless
+    // unresolved dependencies are allowed.
+    //
+    for (dependency_alternative& da: das)
     {
-      // 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, unless unresolved dependencies are allowed.
-      //
-      if (!resolve (d, false /* test */) && !ignore_unresolved)
-        bail (d, "dependency");
+      for (dependency& d: da)
+      {
+        if (!resolve (d, false /* test */) && !ignore_unresolved)
+          bail (d, "dependency");
+      }
     }
   }
 
@@ -1204,10 +1225,13 @@ detect_dependency_cycle (const package_id& id,
   chain.push_back (id);
 
   shared_ptr<package> p (db.load<package> (id));
-  for (const auto& da: p->dependencies)
+  for (const auto& das: p->dependencies)
   {
-    for (const auto& d: da)
-      detect_dependency_cycle (d.package.object_id (), chain, db);
+    for (const auto& da: das)
+    {
+      for (const auto& d: da)
+        detect_dependency_cycle (d.package.object_id (), chain, db);
+    }
   }
 
   chain.pop_back ();
diff --git a/migrate/migrate.cxx b/migrate/migrate.cxx
index 6c66bf0..627ee4f 100644
--- a/migrate/migrate.cxx
+++ b/migrate/migrate.cxx
@@ -208,7 +208,6 @@ create (database& db, bool extra_only) const
 
 // Register the data migration functions for the package database schema.
 //
-#if 0
 template <schema_version v>
 using package_migration_entry_base =
   data_migration_entry<v, LIBBREP_PACKAGE_SCHEMA_VERSION_BASE>;
@@ -223,8 +222,75 @@ struct package_migration_entry: package_migration_entry_base<v>
 static const package_migration_entry<22>
 package_migrate_v22 ([] (database& db)
 {
+  // Note that package_dependency_alternative_dependencies.alternative_index
+  // is copied from package_dependency_alternatives.index and
+  // package_dependency_alternative_dependencies.index is set to 0.
+  //
+  db.execute (
+    "INSERT INTO \"package_dependency_alternative_dependencies\" "
+    "(\"tenant\", "
+    "\"name\", "
+    "\"version_epoch\", "
+    "\"version_canonical_upstream\", "
+    "\"version_canonical_release\", "
+    "\"version_revision\", "
+    "\"dependency_index\", "
+    "\"alternative_index\", "
+    "\"index\", "
+    "\"dep_name\", "
+    "\"dep_min_version_epoch\", "
+    "\"dep_min_version_canonical_upstream\", "
+    "\"dep_min_version_canonical_release\", "
+    "\"dep_min_version_revision\", "
+    "\"dep_min_version_upstream\", "
+    "\"dep_min_version_release\", "
+    "\"dep_max_version_epoch\", "
+    "\"dep_max_version_canonical_upstream\", "
+    "\"dep_max_version_canonical_release\", "
+    "\"dep_max_version_revision\", "
+    "\"dep_max_version_upstream\", "
+    "\"dep_max_version_release\", "
+    "\"dep_min_open\", "
+    "\"dep_max_open\", "
+    "\"dep_package_tenant\", "
+    "\"dep_package_name\", "
+    "\"dep_package_version_epoch\", "
+    "\"dep_package_version_canonical_upstream\", "
+    "\"dep_package_version_canonical_release\", "
+    "\"dep_package_version_revision\") "
+    "SELECT "
+    "\"tenant\", "
+    "\"name\", "
+    "\"version_epoch\", "
+    "\"version_canonical_upstream\", "
+    "\"version_canonical_release\", "
+    "\"version_revision\", "
+    "\"dependency_index\", "
+    "\"index\", "
+    "0, "
+    "\"dep_name\", "
+    "\"dep_min_version_epoch\", "
+    "\"dep_min_version_canonical_upstream\", "
+    "\"dep_min_version_canonical_release\", "
+    "\"dep_min_version_revision\", "
+    "\"dep_min_version_upstream\", "
+    "\"dep_min_version_release\", "
+    "\"dep_max_version_epoch\", "
+    "\"dep_max_version_canonical_upstream\", "
+    "\"dep_max_version_canonical_release\", "
+    "\"dep_max_version_revision\", "
+    "\"dep_max_version_upstream\", "
+    "\"dep_max_version_release\", "
+    "\"dep_min_open\", "
+    "\"dep_max_open\", "
+    "\"dep_package_tenant\", "
+    "\"dep_package_name\", "
+    "\"dep_package_version_epoch\", "
+    "\"dep_package_version_canonical_upstream\", "
+    "\"dep_package_version_canonical_release\", "
+    "\"dep_package_version_revision\" "
+    "FROM \"package_dependency_alternatives\"");
 });
-#endif
 
 // Register the data migration functions for the build database schema.
 //
diff --git a/mod/mod-package-version-details.cxx b/mod/mod-package-version-details.cxx
index 90c33b1..68d43de 100644
--- a/mod/mod-package-version-details.cxx
+++ b/mod/mod-package-version-details.cxx
@@ -320,31 +320,33 @@ handle (request& rq, response& rs)
       << TABLE(CLASS="proplist", ID="depends")
       <<   TBODY;
 
-    for (const auto& da: ds)
+    for (const auto& das: ds)
     {
       s << TR(CLASS="depends")
         <<   TH;
 
-      if (da.conditional)
+      if (das.conditional)
         s << '?';
 
-      if (da.buildtime)
+      if (das.buildtime)
         s << '*';
 
       s <<   ~TH
         <<   TD
         <<     SPAN(CLASS="value");
 
-      for (const auto& d: da)
+      for (const auto& da: das)
       {
-        if (&d != &da[0])
+        if (&da != &das[0])
           s << " | ";
 
-        print_dependency (d);
+        assert (da.size () == 1); // @@ DEP
+
+        print_dependency (da[0]);
       }
 
       s <<     ~SPAN
-        <<     SPAN_COMMENT (da.comment)
+        <<     SPAN_COMMENT (das.comment)
         <<   ~TD
         << ~TR;
     }
@@ -360,34 +362,34 @@ handle (request& rq, response& rs)
       << TABLE(CLASS="proplist", ID="requires")
       <<   TBODY;
 
-    for (const auto& ra: rm)
+    for (const auto& ras: rm)
     {
       s << TR(CLASS="requires")
         <<   TH;
 
-      if (ra.conditional)
+      if (ras.conditional)
         s << "?";
 
-      if (ra.buildtime)
+      if (ras.buildtime)
         s << "*";
 
-      if (ra.conditional || ra.buildtime)
+      if (ras.conditional || ras.buildtime)
         s << " ";
 
       s <<   ~TH
         <<   TD
         <<     SPAN(CLASS="value");
 
-      for (const auto& r: ra)
+      for (const auto& ra: ras)
       {
-        if (&r != &ra[0])
+        if (&ra != &ras[0])
           s << " | ";
 
-        s << r;
+        s << ra;
       }
 
       s <<     ~SPAN
-        <<     SPAN_COMMENT (ra.comment)
+        <<     SPAN_COMMENT (ras.comment)
         <<   ~TD
         << ~TR;
     }
diff --git a/mod/page.cxx b/mod/page.cxx
index f2f1843..af9c795 100644
--- a/mod/page.cxx
+++ b/mod/page.cxx
@@ -416,22 +416,26 @@ namespace brep
     if (!dependencies_.empty ())
       s << "; ";
 
-    for (const auto& d: dependencies_)
+    for (const dependency_alternatives& das: dependencies_)
     {
-      if (&d != &dependencies_[0])
+      if (&das != &dependencies_[0])
         s << ", ";
 
-      if (d.conditional)
+      if (das.conditional)
         s << "?";
 
-      if (d.buildtime)
+      if (das.buildtime)
         s << "*";
 
       // Suppress package name duplicates.
       //
       set<package_name> names;
-      for (const auto& da: d)
-        names.emplace (da.name);
+      for (const dependency_alternative& da: das)
+      {
+        assert (da.size () == 1); // @@ DEP
+
+        names.emplace (da[0].name);
+      }
 
       bool mult (names.size () > 1);
 
@@ -439,9 +443,13 @@ namespace brep
         s << "(";
 
       bool first (true);
-      for (const auto& da: d)
+      for (const dependency_alternative& da: das)
       {
-        const package_name& n (da.name);
+        assert (da.size () == 1); // @@ DEP
+
+        const dependency& d (da[0]);
+
+        const package_name& n (d.name);
         if (names.find (n) != names.end ())
         {
           names.erase (n);
@@ -454,9 +462,9 @@ namespace brep
           // Try to display the dependency as a link if it is resolved.
           // Otherwise display it as plain text.
           //
-          if (da.package != nullptr)
+          if (d.package != nullptr)
           {
-            shared_ptr<package> p (da.package.load ());
+            shared_ptr<package> p (d.package.load ());
             assert (p->internal () || !p->other_repositories.empty ());
 
             shared_ptr<repository> r (
@@ -507,23 +515,23 @@ namespace brep
       <<     SPAN(CLASS="value")
       <<       requirements_.size () << "; ";
 
-    for (const auto& r: requirements_)
+    for (const auto& ras: requirements_)
     {
-      if (&r != &requirements_[0])
+      if (&ras != &requirements_[0])
         s << ", ";
 
-      if (r.conditional)
+      if (ras.conditional)
         s << "?";
 
-      if (r.buildtime)
+      if (ras.buildtime)
         s << "*";
 
-      if (r.empty ())
+      if (ras.empty ())
       {
         // If there is no requirement alternatives specified, then print the
         // comment first word.
         //
-        const auto& c (r.comment);
+        const auto& c (ras.comment);
         if (!c.empty ())
         {
           auto n (c.find (' '));
@@ -535,14 +543,14 @@ namespace brep
       }
       else
       {
-        bool mult (r.size () > 1);
+        bool mult (ras.size () > 1);
 
         if (mult)
           s << "(";
 
-        for (const auto& ra: r)
+        for (const auto& ra: ras)
         {
-          if (&ra != &r[0])
+          if (&ra != &ras[0])
             s << " | ";
 
           s << ra;
diff --git a/tests/load/driver.cxx b/tests/load/driver.cxx
index 51627b7..25403c7 100644
--- a/tests/load/driver.cxx
+++ b/tests/load/driver.cxx
@@ -270,7 +270,7 @@ test_git_repos (const cstrings& loader_args,
     assert (p->dependencies.size () == 1);
     assert (p->dependencies[0].size () == 1);
 
-    assert (p->dependencies[0][0] ==
+    assert (p->dependencies[0][0][0] ==
             dep ("libmisc",
                  version_constraint (
                    dep_ver ("1.0"), false, dep_ver ("1.0"), false)));
@@ -466,12 +466,12 @@ test_pkg_repos (const cstrings& loader_args,
     assert (fpv2->dependencies[0].size () == 1);
     assert (fpv2->dependencies[1].size () == 1);
 
-    assert (fpv2->dependencies[0][0] ==
+    assert (fpv2->dependencies[0][0][0] ==
             dep ("libbar",
                  version_constraint (
                    nullopt, true, dep_ver ("2.4.0"), false)));
 
-    assert (fpv2->dependencies[1][0] ==
+    assert (fpv2->dependencies[1][0][0] ==
             dep ("libexp",
                  version_constraint (
                    dep_ver ("+2-1.2"), false, dep_ver ("+2-1.2"), false)));
@@ -513,27 +513,27 @@ test_pkg_repos (const cstrings& loader_args,
     assert (fpv2a->dependencies[1].size () == 1);
     assert (fpv2a->dependencies[2].size () == 2);
 
-    assert (fpv2a->dependencies[0][0] ==
+    assert (fpv2a->dependencies[0][0][0] ==
             dep ("libmisc",
                  version_constraint (
                    dep_ver ("0.1"), false, dep_ver ("2.0.0-"), true)));
 
-    assert (fpv2a->dependencies[0][1] ==
+    assert (fpv2a->dependencies[0][1][0] ==
             dep ("libmisc",
                  version_constraint (
                    dep_ver ("2.0"), false, dep_ver ("5.0"), false)));
 
-    assert (fpv2a->dependencies[1][0] ==
+    assert (fpv2a->dependencies[1][0][0] ==
             dep ("libgenx",
                  version_constraint (
                    dep_ver ("0.2"), true, dep_ver ("3.0"), true)));
 
-    assert (fpv2a->dependencies[2][0] ==
+    assert (fpv2a->dependencies[2][0][0] ==
             dep ("libexpat",
                  version_constraint (
                    nullopt, true, dep_ver ("5.2"), true)));
 
-    assert (fpv2a->dependencies[2][1] ==
+    assert (fpv2a->dependencies[2][1][0] ==
             dep ("libexpat",
                  version_constraint (
                    dep_ver ("1"), true, dep_ver ("5.1"), false)));
@@ -573,7 +573,7 @@ test_pkg_repos (const cstrings& loader_args,
 
     assert (fpv3->dependencies.size () == 1);
     assert (fpv3->dependencies[0].size () == 1);
-    assert (fpv3->dependencies[0][0] ==
+    assert (fpv3->dependencies[0][0][0] ==
             dep ("libmisc",
                  version_constraint (
                    dep_ver ("2.0.0"), false, nullopt, true)));
@@ -612,7 +612,7 @@ test_pkg_repos (const cstrings& loader_args,
 
     assert (fpv4->dependencies.size () == 1);
     assert (fpv4->dependencies[0].size () == 1);
-    assert (fpv4->dependencies[0][0] ==
+    assert (fpv4->dependencies[0][0][0] ==
             dep ("libmisc",
                  version_constraint (
                    dep_ver ("2.0.0"), false, nullopt, true)));
@@ -696,13 +696,13 @@ test_pkg_repos (const cstrings& loader_args,
 
     assert (xpv->dependencies.size () == 2);
     assert (xpv->dependencies[0].size () == 1);
-    assert (xpv->dependencies[0][0] ==
+    assert (xpv->dependencies[0][0][0] ==
             dep ("libexpat",
                  version_constraint (
                    dep_ver ("2.0.0"), false, nullopt, true)));
 
     assert (xpv->dependencies[1].size () == 1);
-    assert (xpv->dependencies[1][0] == dep ("libgenx", nullopt));
+    assert (xpv->dependencies[1][0][0] == dep ("libgenx", nullopt));
 
     assert (xpv->requirements.empty ());
 
@@ -783,12 +783,12 @@ test_pkg_repos (const cstrings& loader_args,
     assert (fpv5->dependencies[0].comment ==
             "Crashes with 1.1.0-2.3.0.");
 
-    assert (fpv5->dependencies[0][0] ==
+    assert (fpv5->dependencies[0][0][0] ==
             dep ("libmisc",
                  version_constraint (
                    nullopt, true, dep_ver ("1.1"), true)));
 
-    assert (fpv5->dependencies[0][1] ==
+    assert (fpv5->dependencies[0][1][0] ==
             dep ("libmisc",
                  version_constraint (
                    dep_ver ("2.3.0+0"), true, nullopt, true)));
@@ -796,7 +796,7 @@ test_pkg_repos (const cstrings& loader_args,
     assert (fpv5->dependencies[1].size () == 1);
     assert (fpv5->dependencies[1].comment.empty ());
 
-    assert (fpv5->dependencies[1][0] ==
+    assert (fpv5->dependencies[1][0][0] ==
             dep ("libexp",
                  version_constraint (
                    dep_ver ("1.0"), false, nullopt, true)));
@@ -804,8 +804,8 @@ test_pkg_repos (const cstrings& loader_args,
     assert (fpv5->dependencies[2].size () == 2);
     assert (fpv5->dependencies[2].comment == "The newer the better.");
 
-    assert (fpv5->dependencies[2][0] == dep ("libstudxml", nullopt));
-    assert (fpv5->dependencies[2][1] == dep ("libexpat", nullopt));
+    assert (fpv5->dependencies[2][0][0] == dep ("libstudxml", nullopt));
+    assert (fpv5->dependencies[2][1][0] == dep ("libexpat", nullopt));
 
     requirements& fpvr5 (fpv5->requirements);
     assert (fpvr5.size () == 5);
@@ -867,10 +867,10 @@ test_pkg_repos (const cstrings& loader_args,
 
     assert (epv->dependencies.size () == 2);
     assert (epv->dependencies[0].size () == 1);
-    assert (epv->dependencies[0][0] == dep ("libmisc", nullopt));
+    assert (epv->dependencies[0][0][0] == dep ("libmisc", nullopt));
 
     assert (epv->dependencies[1].size () == 1);
-    assert (epv->dependencies[1][0] ==
+    assert (epv->dependencies[1][0][0] ==
             dep ("libpq",
                  version_constraint (
                    dep_ver ("9.0.0"), false, nullopt, true)));