https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85007
--- Comment #12 from Eric Reischer <emr-gnu at hev dot psu.edu> --- It's in there on my target system; I just missed it when I was transcribing over into the report. It looks from gnatlink.adb:540 (of 7.3.0), if the "--GCC=" flag is specified, it short-circuits all other args that normally would have been passed to the linker, including the optimization level, "-m32", "--RTS=32", and any other flags that were passed in the compiler section of the GPR file.