When I look at the config.cache file on Cygwin 2.9, and in particular the
*_works variable whose value is 'no', I see a number of issues that could
be worth fixing in Cygwin. You find the test case in the corresponding *.m4
file.
* chown.m4
gl_cv_func_chown_ctime_works=no
* fchmodat.m4
gl_cv_func_fchmodat_works=no
* fcntl.m4
gl_cv_func_fcntl_f_dupfd_works=no
* fma.m4
gl_cv_func_fma_works=no
* fmaf.m4
gl_cv_func_fmaf_works=no
* fmal.m4
gl_cv_func_fmal_works=no
* frexpl.m4
gl_cv_func_frexpl_works=no
* getdtablesize.m4
gl_cv_func_getdtablesize_works=no
* ilogbl.m4
gl_cv_func_ilogbl_works=no
* log2.m4
gl_cv_func_log2_works=no
* log2f.m4
gl_cv_func_log2f_works=no
* pwrite.m4
gl_cv_func_pwrite_works=no
* strtod.m4
gl_cv_func_strtod_works=no
* strfmon_l.m4
gl_cv_strfmon_l_works=no
* uchar.m4
gl_cv_type_char16_t_works=no
gl_cv_type_char32_t_works=no
There are surely more issues, listed in *.m4 files or in the documentation,
but it's harder to get a list of.