This commit seems to have broken ash, causing some sort of memory corruption: http://git.busybox.net/busybox/commit/shell/ash.c?id=4ba6c5d3ba3d2c7922aff6b5c2e73b8325f1cf17 I don't know of a self-contained test case, but musl's configure script is crashing. Reverting this commit makes it work again. Rich