https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102746
--- Comment #2 from Илья Шипицин <chipitsine at gmail dot com> --- I came to this situation using wrong powershell approach. I found all "gcda" and merged them into single string. Powershell executed "gcov" and passed 1 (!!) argument as concatenated string. Actually, if gcov cannot find some required file, it should return "1" (or other non zero).