[PATCH v2 1/2] rust: pick a GCC-compatible Cargo target under MSYS2/MinGW
From: Johannes Schindelin via GitGitGadget <hidden>
Date: 2026-09-11 19:08:55
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
From: Johannes Schindelin <redacted>
When Git is built under MSYS2/MinGW with Rust support enabled, the
Makefile expects `cargo build` to drop a `target/release/libgitcore.a`
that is linkable by the same MinGW GCC used for every other object.
With Rust installed via `rustup` (the way it ships on the
GitHub-hosted `windows-2022` and `windows-11-arm` runners that build
microsoft/git), the default toolchain targets the MSVC ABI; cargo
then writes `target/release/gitcore.lib` instead, which the MinGW
`ld.exe` cannot consume:
LINK git-shell.exe
D:\git-sdk-64-minimal\mingw64\bin/ld.exe: cannot find target/release/libgitcore.a: No such file or directory
collect2.exe: error: ld returned 1 exit status
See https://github.com/microsoft/git/actions/runs/27341625000 for the
full log.
Let's define the correct target. Re-use (and fix) the existing
`HOST_CPU` variable for that purpose. Avoid relying on environment
variables that are simply not defined in Git for Windows' minimal SDK
that Git uses in its CI runs.
Assisted-by: Claude Opus 4.7
Signed-off-by: Johannes Schindelin <redacted>
---
Makefile | 3 ++-
config.mak.uname | 24 +++++++++++++++++++++++-
2 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index fac3e8879c..bf2a11c08a 100644
--- a/Makefile
+++ b/Makefile@@ -959,7 +959,7 @@ RUST_LIB_NAME = gitcore.lib else RUST_LIB_NAME = libgitcore.a endif -RUST_LIB = target/$(RUST_BUILD_CONFIG)/$(RUST_LIB_NAME) +RUST_LIB = target$(if $(CARGO_TARGET),/$(CARGO_TARGET))/$(RUST_BUILD_CONFIG)/$(RUST_LIB_NAME) endif GITLIBS = common-main.o $(LIB_FILE)
@@ -993,6 +993,7 @@ endif ifndef DEBUG CARGO_ARGS += --release endif +CARGO_ARGS += $(if $(CARGO_TARGET),--target $(CARGO_TARGET)) # For the 'sparse' target SPARSE_FLAGS ?= -std=gnu99 -D__STDC_NO_VLA__
diff --git a/config.mak.uname b/config.mak.uname
index 0b63be10b7..720d9ba3ed 100644
--- a/config.mak.uname
+++ b/config.mak.uname@@ -758,7 +758,29 @@ ifeq ($(uname_S),MINGW) MINGW_PREFIX := /$(shell echo '$(MSYSTEM)' | tr A-Z a-z) endif prefix = $(MINGW_PREFIX) - HOST_CPU = $(patsubst %-w64-mingw32,%,$(MINGW_CHOST)) + + # A rustup-managed Rust on Windows defaults to the MSVC ABI and + # produces a `gitcore.lib` that the MinGW `ld.exe` cannot link. + # Pick a GCC-compatible Rust target triple matching the MSYS2 + # subsystem instead: `*-pc-windows-gnullvm` for the Clang/LLVM + # subsystems (which on Windows is also the only choice for + # ARM64, where no MinGW-GCC port exists) and `*-pc-windows-gnu` + # for the MSVCRT-based MinGW subsystems. For a `staticlib` + # crate-type Cargo does not invoke an external linker, so + # `rustup target add <triple>` is sufficient. + ifneq (,$(filter %ARM64, $(MSYSTEM))) + HOST_CPU = aarch64 + else ifneq (,$(filter %32, $(MSYSTEM))) + HOST_CPU = i686 + else + HOST_CPU = x86_64 + endif + ifneq (,$(filter CLANG%, $(MSYSTEM))) + CARGO_TARGET = $(HOST_CPU)-pc-windows-gnullvm + else + CARGO_TARGET = $(HOST_CPU)-pc-windows-gnu + endif + BASIC_LDFLAGS += -Wl,--pic-executable COMPAT_CFLAGS += -DDETECT_MSYS_TTY \ -DENSURE_MSYSTEM_IS_SET="\"$(MSYSTEM)\"" \
--
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