Stripping `-lmingwex` from the Fortran default linker flags can lead to a situation where the first `-lmsvcrt` appears before the first `-lmingwex` for a library that consists of Fortran and C++ sources. That means that the linker picks some functions from the Windows CRT that should instead be picked from `libmingwex.a`.
It took quite some time to figure out an odd behavior when calling `std::asin` with a complex double precision value with a real part larger than 1.0 and an imaginary part of 0.0 in such a library. See also: https://octave.discourse.group/t/6026/75 Also don't strip `-lmoldname` from these flags because omitting that library could result in issues when Fortran code tries to call POSIX-like C functions without a `_` prefix when targeting MinGW. The following change fixes these issues by essentially reverting the changes from: https://lists.gnu.org/r/autoconf-patches/2021-09/msg00000.html I'm not sure why `-lkernel32` needs to be removed from the linker flags when targeting MinGW. But we didn't observe an issue with that, so I left that as applied in that changeset. diff -urN autoconf-2.72/lib/autoconf/fortran.m4.orig autoconf-2.72/lib/autoconf/fortran.m4 --- autoconf-2.72/lib/autoconf/fortran.m4.orig 2024-10-30 13:31:24.456674400 +0100 +++ autoconf-2.72/lib/autoconf/fortran.m4 2024-12-11 16:08:46.415095400 +0100 @@ -705,7 +705,7 @@ -lang* | -lcrt*.o | -lc | -lgcc* | -lSystem | -libmil | -little \ |-LANG:=* | -LIST:* | -LNO:* | -link) ;; - -lkernel32 | -lmingw* | -lmoldname) + -lkernel32) # Ignore this library only on Windows-like systems. case $host_os in cygwin* | msys* | mingw* | windows*) ;;
