Hi Ezekiel,

On Thu, 20 Nov 2025, Ezekiel Newren wrote:

This is a retrospective review. I completely missed this patch series,
and only noticed its existence after it was merged into master. The
core problem is that these changes assume that windows builds only
ever use the MSVC compiler, but that's not true.

Correct. I had actually worked on a solution to this in Git for Windows,
but due to time constraints (after factoring in the usual time tax, other
priorities dictated that I wouldn't have time to see it through) I hadn't
had time to contribute it, let alone engage in reviewing Patrick's patches
(I had actually not even seen them until I had written the patch and
verified that it fixed the issue).

Here is my patch (with proper handling of MSVC, but obviously it no longer
applies without conflicts):
https://github.com/git-for-windows/git/commit/0949ff2ad5d1d085b10c63029c65293416732851

-- snipsnap --
From 0949ff2ad5d1d085b10c63029c65293416732851 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <redacted>
Date: Fri, 24 Oct 2025 14:49:22 +0200
Subject: [PATCH] meson(cargo): support Windows again

For over a year, Git has been moved to a more modern build system than
it had before (GNU make, or on Windows optionally CMake). Naturally,
this new system breaks Windows support left and right.

For example, c184795fc0e (meson: add infrastructure to build internal
Rust library, 2025-10-02) added support for building a Rust library, and
it fails when Visual C is configured as compiler.

This is the reason that the `win+Meson` job of Git's `master` branch
fails for the past 16 days, i.e. the latest 9 pushes of the `master`
branch as of time of writing. The symptom is:

  [697/905] Generating src/git_rs with a custom command
  FAILED: [code=1] src/libgitcore.a "C:\Program Files\Git\bin\sh.exe" "D:/a/git/git/src/cargo-meson.sh" "D:/a/git/git" "D:/a/git/git/build/src" "--release"
  cp: cannot stat 'D:/a/git/git/build/src/release/libgitcore.a': No such file or directory

The reason is that Visual C's output is called `gitcore.lib`, not
`libgitcore.a`. Let's special-case Visual C and use the correct filename
in all cases.

Signed-off-by: Johannes Schindelin <redacted>
---
 src/cargo-meson.sh |  7 +++++--
 src/meson.build    | 10 +++++++++-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/cargo-meson.sh b/src/cargo-meson.sh
index 99400986d93..c14a08c592d 100755
--- a/src/cargo-meson.sh
+++ b/src/cargo-meson.sh

@@ -5,6 +5,9 @@ then
 	exit 1
 fi
 
+target="$1"
+shift
+
 SOURCE_DIR="$1"
 BUILD_DIR="$2"
 BUILD_TYPE=debug

@@ -26,7 +29,7 @@ then
 	exit $RET
 fi
 
-if ! cmp "$BUILD_DIR/$BUILD_TYPE/libgitcore.a" "$BUILD_DIR/libgitcore.a" >/dev/null 2>&1
+if ! cmp "$BUILD_DIR/$BUILD_TYPE/$target" "$BUILD_DIR/$target" >/dev/null 2>&1
 then
-	cp "$BUILD_DIR/$BUILD_TYPE/libgitcore.a" "$BUILD_DIR/libgitcore.a"
+	cp "$BUILD_DIR/$BUILD_TYPE/$target" "$BUILD_DIR/$target"
 fi

diff --git a/src/meson.build b/src/meson.build
index 25b9ad5a147..b2473c46994 100644
--- a/src/meson.build
+++ b/src/meson.build

@@ -3,6 +3,13 @@ libgit_rs_sources = [
   'varint.rs',
 ]
 
+# The exact file name depends on the compiler
+if meson.get_compiler('c').get_id() == 'msvc'
+  target = 'gitcore.lib'
+else
+  target = 'libgitcore.a'
+endif
+
 # Unfortunately we must use a wrapper command to move the output file into the
 # current build directory. This can fixed once `cargo build --artifact-dir`
 # stabilizes. See https://github.com/rust-lang/cargo/issues/6790 for that

@@ -10,6 +17,7 @@ libgit_rs_sources = [
 cargo_command = [
   shell,
   meson.current_source_dir() / 'cargo-meson.sh',
+  target,
   meson.project_source_root(),
   meson.current_build_dir(),
 ]

@@ -21,7 +29,7 @@ libgit_rs = custom_target('git_rs',
   input: libgit_rs_sources + [
     meson.project_source_root() / 'Cargo.toml',
   ],
-  output: 'libgitcore.a',
+  output: target,
   command: cargo_command,
 )
 libgit_dependencies += declare_dependency(link_with: libgit_rs)

-- 
2.51.1.windows.1