vcpkg: support builtin-baseline without git

pkgs/by-name/vc/vcpkg-tool/package.nix

@@ -44,6 +44,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   patches = [
     ./change-lock-location.patch
+    ./read-bundle-info-from-root.patch
   ];
 
   cmakeFlags = [

pkgs/by-name/vc/vcpkg-tool/read-bundle-info-from-root.patch

@@ -0,0 +1,43 @@
+diff --git a/include/vcpkg/vcpkgpaths.h b/include/vcpkg/vcpkgpaths.h
+index 90fd4d09..ebc6342b 100644
+--- a/include/vcpkg/vcpkgpaths.h
++++ b/include/vcpkg/vcpkgpaths.h
+@@ -28,6 +28,8 @@
+
+ namespace vcpkg
+ {
++    Path exported_determine_root(const ReadOnlyFilesystem& fs, const Path& original_cwd, const VcpkgCmdArguments& args);
++
+     struct ToolsetArchOption
+     {
+         ZStringView name;
+diff --git a/src/vcpkg.cpp b/src/vcpkg.cpp
+index 2b62cb55..d7b8ead5 100644
+--- a/src/vcpkg.cpp
++++ b/src/vcpkg.cpp
+@@ -296,7 +296,8 @@ int main(const int argc, const char* const* const argv)
+         Debug::println("To include the environment variables in debug output, pass --debug-env");
+     }
+     args.check_feature_flag_consistency();
+-    const auto current_exe_path = get_exe_path_of_current_process();
++    const auto current_exe_path =
++        exported_determine_root(real_filesystem, real_filesystem.current_path(VCPKG_LINE_INFO), args) / "vcpkg";
+
+     bool to_enable_metrics = true;
+     {
+diff --git a/src/vcpkg/vcpkgpaths.cpp b/src/vcpkg/vcpkgpaths.cpp
+index 77e107f5..132050ba 100644
+--- a/src/vcpkg/vcpkgpaths.cpp
++++ b/src/vcpkg/vcpkgpaths.cpp
+@@ -518,6 +518,11 @@ namespace
+
+ namespace vcpkg
+ {
++    Path exported_determine_root(const ReadOnlyFilesystem& fs, const Path& original_cwd, const VcpkgCmdArguments& args)
++    {
++        return determine_root(fs, original_cwd, args);
++    }
++
+     Path InstalledPaths::listfile_path(const BinaryParagraph& pgh) const
+     {
+         return this->vcpkg_dir_info() / (pgh.fullstem() + ".list");

pkgs/by-name/vc/vcpkg/package.nix

@@ -14,7 +14,24 @@ stdenvNoCC.mkDerivation (finalAttrs: {
     owner = "microsoft";
     repo = "vcpkg";
     rev = finalAttrs.version;
-    hash = "sha256-HT7IcznN5W+Innzg0aeOvZnpVUTf/uJFlYflE91YJQA=";
+    hash = "sha256-WE+BeF9BYR9/Gmi60g6ApXsWQ2vch2N6XhH1A9HAHsc=";
+    leaveDotGit = true;
+    postFetch = ''
+      cd "$out"
+      VCPKG_BASELINE_COMMIT_SHA=$(git rev-parse --verify HEAD)
+      # We only needed the .git folder for that previous command, so we can safely delete it now.
+      # If we don’t delete it, then we might run into problems (see #8567).
+      rm -r .git
+      # Here's the code that Creates this json file in Visual Studio deployment and the code that reads it:
+      #   https://github.com/microsoft/vcpkg-tool/blob/f098d3e0aaa7e46ea84a1f7079586e1ec5af8ab5/vcpkg-init/mint-standalone-bundle.ps1#L21
+      #   https://github.com/microsoft/vcpkg-tool/blob/f098d3e0aaa7e46ea84a1f7079586e1ec5af8ab5/src/vcpkg/bundlesettings.cpp#L87
+      #
+      # Here's the code that we target with this setting. If we use embeddedsha combined with usegitregistry, vcpkg
+      # will checkout a remote instead of trying to do git operation in the vcpkg root
+      #   https://github.com/microsoft/vcpkg-tool/blob/d272c0d4f5175b26bd56c6109d4c4935b791a157/src/vcpkg/vcpkgpaths.cpp#L920
+      #   https://github.com/microsoft/vcpkg-tool/blob/d272c0d4f5175b26bd56c6109d4c4935b791a157/src/vcpkg/configuration.cpp#L718
+      echo '{ "readonly": true, "usegitregistry": true, "deployment": "Git", "embeddedsha": "'"$VCPKG_BASELINE_COMMIT_SHA"'" }' > vcpkg-bundle.json
+    '';
   };
 
   nativeBuildInputs = [ makeWrapper ];
@@ -36,7 +53,7 @@ stdenvNoCC.mkDerivation (finalAttrs: {
       runHook preInstall
 
       mkdir -p "$out/bin" "$out/share/vcpkg/scripts/buildsystems"
-      cp --preserve=mode -r ./{docs,ports,triplets,scripts,.vcpkg-root,versions,LICENSE.txt} "$out/share/vcpkg/"
+      cp --preserve=mode -r ./{docs,ports,triplets,scripts,.vcpkg-root,versions,LICENSE.txt,vcpkg-bundle.json} "$out/share/vcpkg/"
 
       ${lib.optionalString doWrap ''
         makeWrapper "${vcpkg-tool}/bin/vcpkg" "$out/bin/vcpkg" \
@@ -50,7 +67,7 @@ stdenvNoCC.mkDerivation (finalAttrs: {
     '';
 
   meta = {
-    description = "C++ Library Manager";
+    description = "C++ Library Manager for Windows, Linux, and macOS";
     mainProgram = "vcpkg";
     homepage = "https://vcpkg.io/";
     license = lib.licenses.mit;