# `builtins.warn` requires a string message, so we enforce that in our implementation, so that callers aren't accidentally incompatible with newer Nix versions.
assertisStringmsg;
ifmustAbort
thenbuiltins.trace"[1;31mevaluation warning: ${msg}[0m"(abort"NIX_ABORT_ON_WARN=true; warnings are treated as unrecoverable errors.")