fixupCFlagsForDarwin() {
    # Because it’s getting called from a Darwin stdenv, avr-gcc will pick up on
    # Darwin-specific flags, and it will barf and die on -iframework in
    # particular. Strip them out, so simavr can compile its test firmware.
    cflagsFilter='s|-F[^ ]*||g;s|-iframework [^ ]*||g;s|-isystem [^ ]*||g;s|  *| |g'

    # The `CoreFoundation` reference is added by `linkSystemCoreFoundationFramework` in the
    # Apple SDK’s setup hook. Remove that because avr-gcc will fail due to file not found.
    ldFlagsFilter='s|/nix/store/[^-]*-apple-framework-CoreFoundation[^ ]*||g'

    # `cc-wrapper.sh`` supports getting flags from a system-specific salt. While it is currently a
    # tuple, that’s not considered a stable interface, so the derivation will provide them.
    export NIX_CFLAGS_COMPILE_@darwinSuffixSalt@=${NIX_CFLAGS_COMPILE-}
    export NIX_LDFLAGS_@darwinSuffixSalt@=${NIX_LDFLAGS-}

    echo removing @darwinSuffixSalt@-specific flags from NIX_CFLAGS_COMPILE for @avrSuffixSalt@
    export NIX_CFLAGS_COMPILE_@avrSuffixSalt@+="$(sed "$cflagsFilter" <<< "$NIX_CFLAGS_COMPILE")"
    echo removing @darwinSuffixSalt@-specific flags from NIX_LDFLAGS for @avrSuffixSalt@
    export NIX_LDFLAGS_@avrSuffixSalt@+="$(sed "$ldFlagsFilter;$cflagsFilter" <<< "$NIX_LDFLAGS")"

    # Make sure the global flags aren’t accidentally influencing the platform-specific flags.
    export NIX_CFLAGS_COMPILE=""
    export NIX_LDFLAGS=""
}

# This is pretty hacky, but this hook _must_ run after `linkSystemCoreFoundationFramework`.
function runFixupCFlagsForDarwinLast() {
    preConfigureHooks+=(fixupCFlagsForDarwin)
}

if [ -z "${dontFixupCFlagsForDarwin-}" ]; then
    postUnpackHooks+=(runFixupCFlagsForDarwinLast)
fi