DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 52V5QG5T1587557
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org C5B003857704
MIME-Version: 1.0
Date: Mon, 31 Mar 2025 07:25:32 +0200
Message-ID: <CAE6_+UfTZc0UTb29p=WVXsP7p7sMmOfmd6SOLR8SCPScJEXHRA@mail.gmail.com>
Subject: Crashes in cmake subprocesses since 3.6.0
To: cygwin AT cygwin DOT com
From: Christoph Reiter via Cygwin <cygwin AT cygwin DOT com>
Reply-To: Christoph Reiter <reiter DOT christoph AT gmail DOT com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>

Starting with 3.6.0 when cmake calls into make/ninja/gcc there is a chance of
that failing, for example like this:

CMake Error: Generator: build tool execution failed, command was:
/usr/bin/cmake.exe -E env VERBOSE=1 /usr/bin/make.exe -f Makefile
cmTC_c87e2/fast

* Problem starts with cygwin 3.6.0
* Problem starts with cmake 3.29+ (3.31 is in Cygwin marked as test
and is new enough)
* It doesn't seem to matter which tool is called from cmake
* Downgrading either cmake to 3.28 or cygwin to 3.5.7 makes the problem go away

Instructions for how to reproduce in Cygwin:

* Update Cygwin install to have 3.6.0
* Install the testing version (3.31.3 atm) of cmake
* Run mintty (for some reason in the Windows Terminal it doesn't
reproduce for me)

```
# CMakeLists.txt
cmake_minimum_required(VERSION 3.10)
project(MinimalChecks C)
include(CheckCSourceCompiles)
foreach(i RANGE 1 100)
check_c_source_compiles("int main() { return 0;}" CHECK_${i})
endforeach()
```

```
cmake -B _build --fresh
# also fails: cmake -B _build --fresh -DCMAKE_MAKE_PROGRAM="echo"
```

Expected: 100 times "Success"

Actual: sometimes "Failed"

Related downstream issue with a bit more context/history:
https://github.com/msys2/msys2-runtime/issues/272#issuecomment-2764714256

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple