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diff --git a/libbutl/host-os-release.hxx b/libbutl/host-os-release.hxx
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+// file      : libbutl/host-os-release.hxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include <libbutl/optional.hxx>
+#include <libbutl/target-triplet.hxx>
+
+#include <libbutl/export.hxx>
+
+namespace butl
+{
+  // Information extracted from /etc/os-release on Linux. See os-release(5)
+  // for background. For other platforms we derive the equivalent information
+  // from other sources. Some examples:
+  //
+  // {"debian", {}, "10", "",
+  //  "Debian GNU/Linux", "buster", ""}
+  //
+  // {"fedora", {}, "35", "workstation",
+  //  "Fedora Linux", "", "Workstation Edition"}
+  //
+  // {"ubuntu", {"debian"}, "20.04", "",
+  //  "Ubuntu", "focal", ""}
+  //
+  // {"macos", {}, "12.5", "",
+  //  "Mac OS", "", ""}
+  //
+  // {"freebsd", {}, "13.1", "",
+  //  "FreeBSD", "", ""}
+  //
+  // {"windows", {}, "10", "",
+  //  "Windows", "", ""}
+  //
+  // Note that for Mac OS, the version is the Mac OS version (as printed by
+  // sw_vers) rather than Darwin version (as printed by uname).
+  //
+  // For Windows we currently do not distinguish the Server edition and the
+  // version mapping is as follows:
+  //
+  // Windows 11             11
+  // Windows 10             10
+  // Windows 8.1            8.1
+  // Windows 8              8
+  // Windows 7              7
+  // Windows Vista          6
+  // Windows XP Pro/64-bit  5.2
+  // Windows XP             5.1
+  // Windows 2000           5
+  //
+  // Note that version_id may be empty, for example, on Debian testing:
+  //
+  // {"debian", {}, "", "",
+  //  "Debian GNU/Linux", "", ""}
+  //
+  // Note also that we don't extract PRETTY_NAME because its content is
+  // unpredictable. For example, it may include variant, as in "Fedora Linux
+  // 35 (Workstation Edition)". Instead, construct it from the individual
+  // components as appropriate, normally "$name $version ($version_codename)".
+  //
+  struct os_release
+  {
+    std::string              name_id;    // ID
+    std::vector<std::string> like_ids;   // ID_LIKE
+    std::string              version_id; // VERSION_ID
+    std::string              variant_id; // VARIANT_ID
+
+    std::string name;             // NAME
+    std::string version_codename; // VERSION_CODENAME
+    std::string variant;          // VARIANT
+  };
+
+  // Return the release information for the specified host or nullopt if the
+  // specific host is unknown/unsupported. Throw std::runtime_error if
+  // anything goes wrong.
+  //
+  // Note that "host" here implies that we may be running programs, reading
+  // files, examining environment variables, etc., of the machine we are
+  // running on.
+  //
+  LIBBUTL_SYMEXPORT optional<os_release>
+  host_os_release (const target_triplet& host);
+}