Bug#989862: gcc-mingw-w64: coverage is completely broken

[Stephen Kitt]

Package: gcc-mingw-w64
Version: 22~exp1
Severity: important

Dear Maintainer,

Ever since gcc-mingw-w64 was updated to use GCC 8, gcov has been
broken:

$ x86_64-w64-mingw32-gcc -fprofile-generate -x c - <<<'void main(){}'
/usr/bin/x86_64-w64-mingw32-ld: /tmp/user/1000/ccBN30sM.o::(.text+0x29): undefined reference to `__gcov_indirect_call_profiler_v4'
/usr/bin/x86_64-w64-mingw32-ld: /tmp/user/1000/ccBN30sM.o::(.data+0x98): undefined reference to `__gcov_merge_time_profile'
/usr/bin/x86_64-w64-mingw32-ld: /tmp/user/1000/ccBN30sM.o::(.rdata$.refptr.__gcov_time_profiler_counter[.refptr.__gcov_time_profiler_counter]+0x0): undefined reference to `__gcov_time_profiler_counter'
/usr/bin/x86_64-w64-mingw32-ld: /tmp/user/1000/ccBN30sM.o::(.rdata$.refptr.__gcov_indirect_call[.refptr.__gcov_indirect_call]+0x0): undefined reference to `__gcov_indirect_call'
collect2: error: ld returned 1 exit status

This also renders PGO unusable.

See
https://bugs.launchpad.net/ubuntu/+source/gcc-mingw-w64/+bug/1883933
and
https://bugs.launchpad.net/ubuntu/+source/gcc-mingw-w64/+bug/1920988
for related issues.

Regards,

Stephen


-- System Information:
Debian Release: 10.9
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-debug'), (500, 'stable'), (100, 'unstable-debug'), (100, 'testing-debug'), (100, 'unstable'), (100, 'testing'), (1, 'experimental-debug'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386, arm64

Kernel: Linux 4.19.0-12-amd64 (SMP w/8 CPU cores)
Kernel taint flags: TAINT_WARN, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages gcc-mingw-w64 depends on:
ii gcc-mingw-w64-i686 10-20200402-1+23~exp1
ii gcc-mingw-w64-x86-64 10-20200402-1+23~exp1

gcc-mingw-w64 recommends no packages.

gcc-mingw-w64 suggests no packages.

-- no debconf information