I would file a bug, but that link you provided takes me to a sign-up page that says, "Account creation restricted. Please contact ... response within 24 hours..."
A quick cursory glace of GCC sources would suggest the issue is in \gcc\coverage.c. This is a snippit of a function that builds the mangled path for the .gcda file. if (profile_data_prefix) { #if HAVE_DOS_BASED_FILE_SYSTEM const char *separator = "\\"; #else const char *separator = "/"; #endif filename = concat (getpwd (), separator, filename, NULL); filename = mangle_path (filename); len = strlen (filename); } I'm not an expert on building gcc. I just suspect that somewhere in the build chain HAVE_DOS_BASED_FILE_SYSTEM is getting defined for or by cygwin. Another cursory search of gcc sources suggest HAVE_DOS_BASED_FILE_SYSTEM is defined by this preprocessor stuff: #if defined(__MSDOS__) || defined(_WIN32) || defined(__OS2__) || defined (__CYGWIN__) # ifndef HAVE_DOS_BASED_FILE_SYSTEM # define HAVE_DOS_BASED_FILE_SYSTEM 1 # endif Still a gcc bug? I'm guessing so. On Sun, Apr 12, 2020 at 4:26 AM JonY via Cygwin <cygwin@cygwin.com> wrote: > On 4/12/20 10:59 AM, John Selbie via Cygwin wrote: > > Sure, but this bug is unique to cygwin. Why would that be there bug? > > > > Because Cygwin does not modify gcc to use Windows paths. > > -- > 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 > -- 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