The problem is that Cygwin (on which MinGW and Git Bash are based) tries to read the contents of the executable file, rather than just executing it. The type of link used by Windows here cannot be read as a normal file.

The provided workaround is the best we can offer. Someone who is allowed to handle GPL code without impacting their job (not me) could try removing whatever additional check is being attempted here in Cygwin.