This is an auto-filed bug because dev-lang/mlton does not respect LDFLAGS. The issue was originally discovered on amd64, but it may be reproducible on other arches as well. If you think that a different summary clarifies the issue better, feel free to change it. Attached build log and emerge --info. NOTE: To reproduce this issue you may want to set LDFLAGS="${LDFLAGS} -Wl,--defsym=__gentoo_check_ldflags__=0". If this is not something about c/c++ context you may want to see this bug as an hint to hide the QA warning (with QA_FLAGS_IGNORED) where is not possible to respect LDFLAGS.
Created attachment 643210 [details] build.log build log and emerge --info
tinderbox has reproduced this issue with version 20180207 - Updating summary.