Fix unbound env variable error in tool script
Forgot that our strict options would make this fail.
@@ -73,7 +73,7 @@ if [[ $os = cygwin ]]; then
# user doesn't have gcc-core installed. I have no idea if that actually
# happens. So we'll just explicitly set it to gcc. This might mess up people
# who have clang installed but not gcc, I guess? Is that even possible?
- case $CC in
+ case $cc_exe in
i686-w64-mingw32-gcc.exe|\
x86_64-w64-mingw32-gcc.exe)
cc_exe=gcc;;
