Configuring two CMake presets using Visual Studio's vcpkg concurrently fails

[Cyphall]

When configuring two CMake presets concurrently via CLion, with each CMake preset invoking Visual Studio's vcpkg in manifest mode, one of them randomly fails.

Here is the logs of the failing one:

-- Running vcpkg install
Fetching registry information from https://github.com/microsoft/vcpkg (HEAD)...
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for boost-optional
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for boost-scope
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for glfw3
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for glm
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for magic-enum
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for spdlog
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for vcpkg-cmake
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for vcpkg-cmake-config
error: "c:\program files\git\cmd\git.exe" "--git-dir=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git\.git" "--work-tree=C:\Users\Cyphall\AppData\Local\vcpkg\registries\git" -c core.autocrlf=false init failed with exit code 128
fatal: cannot copy 'C:/Program Files/Git/mingw64/share/git-core/templates/hooks/commit-msg.sample' to 'C:/Users/Cyphall/AppData/Local/vcpkg/registries/git/.git/hooks/commit-msg.sample': File exists

while loading baseline version for vulkan-headers
-- Running vcpkg install - failed
CMake Error at C:/Program Files/Microsoft Visual Studio/18/Community/VC/vcpkg/scripts/buildsystems/vcpkg.cmake:953 (message):
  vcpkg install failed.  See logs for more information:
  C:\Projects\CPP\CyphGPU\build\Windows-MSVC-Profile\vcpkg-manifest-install.log
Call Stack (most recent call first):
  C:/Users/Cyphall/AppData/Local/Programs/CLion/bin/cmake/win/x64/share/cmake-4.2/Modules/CMakeDetermineSystem.cmake:146 (include)
  CMakeLists.txt:5 (project)


CMake Error: CMake was unable to find a build program corresponding to "Ninja".  CMAKE_MAKE_PROGRAM is not set.  You probably need to select a different build tool.
-- Configuring incomplete, errors occurred!

The failure seems to be due to both vcpkg runs using the same registries directory concurrently without any lock.

This issue presumably started happening after the 2026.04.27 release (which includes PR #1938) as before that, the lock was on the VCPKG_ROOT, so two vcpkg runs could not run in parallel at all.

[bugale]

BEEP BOOP! I am Copilot using Bugale's account:

We hit this too, in CI, and I think I can confirm the root cause you suspected — it is exactly "both vcpkg runs using the same registries directory concurrently without any lock", and the culprit is one specific unsynchronized command.

Root cause

VcpkgPaths::git_fetch_from_remote_registry runs git init on the shared registries work tree before taking .vcpkg-lock:

vcpkg-tool/src/vcpkg/vcpkgpaths.cpp

Lines 1047 to 1062 in 60b5cfa

	const auto base_cmd = git_cmd_builder(*git_tool_path, dot_git_dir, work_tree);
	auto init_cmd = base_cmd;
	init_cmd.string_arg("init");
	auto maybe_init_output = cmd_execute_and_capture_output(bdc, init_cmd);
	if (!check_zero_exit_code(bdc, init_cmd, maybe_init_output))
	{
	return LocalizedString::from_raw(bdc.to_string());
	}
	auto lock_file = work_tree / ".vcpkg-lock";
	auto guard = fs.take_exclusive_file_lock(bdc, lock_file);
	if (!guard)
	{
	return LocalizedString::from_raw(bdc.to_string());
	}

auto init_cmd = base_cmd;
init_cmd.string_arg("init");
auto maybe_init_output = cmd_execute_and_capture_output(bdc, init_cmd);   // <-- unsynchronized
...
auto lock_file = work_tree / ".vcpkg-lock";
auto guard = fs.take_exclusive_file_lock(bdc, lock_file);                 // <-- lock taken here

The sibling VcpkgPaths::git_fetch, ~30 lines below, takes the lock first and then runs git init — so the two functions already disagree, and git_fetch is the correct one. There is a lock; git init just runs outside it.

Evidence

GIT_TRACE2_EVENT capture of a live failure (vcpkg 2026-05-27-d5b6777d, 8 concurrent vcpkg install --dry-run sharing one registries cache):

{"event":"start","argv":["git.exe","--git-dir=C:\\race-cache\\git\\.git",
                         "--work-tree=C:\\race-cache\\git","-c","core.autocrlf=false","init"]}
{"event":"cmd_name","name":"init","hierarchy":"init"}
{"event":"error","msg":"could not lock config file C:/race-cache/git/.git/config: File exists"}
{"event":"error","msg":"could not set 'core.repositoryformatversion' to '0'"}
{"event":"exit","code":128}

Same git init, same exit code 128 as yours — different failure mode inside it (.git/config.lock vs your hooks/commit-msg.sample), which is just which part of git init two processes happened to collide on.

Minimal reproducer, no vcpkg involved — concurrent git init on one already-initialized repo, released in the same millisecond:

$dot = 'C:\t\git\.git'; $work = 'C:\t\git'
New-Item -ItemType Directory -Force $work | Out-Null
git --git-dir=$dot --work-tree=$work init | Out-Null

$body = {
    param($dot, $work, $startTicks)
    while ([DateTime]::UtcNow.Ticks -lt $startTicks) { }
    $o = & git "--git-dir=$dot" "--work-tree=$work" -c core.autocrlf=false init 2>&1
    [pscustomobject]@{ Code = $LASTEXITCODE; Out = ($o -join ' | ') }
}

$start = [DateTime]::UtcNow.AddSeconds(3).Ticks
$jobs = 1..6 | ForEach-Object { Start-Job -ScriptBlock $body -ArgumentList $dot, $work, $start }
$jobs | Wait-Job | Receive-Job | Where-Object Code -ne 0

15 iterations x 6 processes → 41/90 failures (45.6%):

[35x] error: could not lock config file C:/t/git/.git/config: File exists
 [5x] fatal: unknown error occurred while reading the configuration files
 [1x] error: invalid config file C:/t/git/.git/config

Those last two are the nastier outcome: a lost race can leave .git/config unreadable, poisoning the cache for later runs instead of only failing the current one.

Fix

I opened #2093, which moves git init inside the lock so it matches git_fetch. Pure statement reorder.

Separately — you were lucky to get a readable error. We hit the identical failure but through get_port_entry instead of get_baseline_version, and that path discards the error and prints <port> does not exist for every port in the registry, with no error: prefix and no git output at all. That is #2094 / #2095.

Workaround until it lands

Give each concurrent invocation its own registries cache — --x-registries-cache=<dir> or X_VCPKG_REGISTRIES_CACHE=<dir> (must be absolute and must already exist). For your CLion case that would mean a distinct directory per CMake preset.

[Cyphall]

Thanks!