Hello, No news about this bug? I was advised to provide a testcase that would fail on Linux too, here is one, which behaves quite like libfakeroot: it redirects chmod into something that uses putenv. $ gcc test.c -o libtest.so -fPIC -shared $ LD_PRELOAD=$PWD/libtest.so perl chmod 0644, "test.c" putting environment *** glibc detected *** perl: munmap_chunk(): invalid pointer: 0x00007fff3cd57df0 *** ======= Backtrace: ========= /lib/x86_64-linux-gnu/libc.so.6(+0x72606)[0x7f3b8b81c606] /usr/lib/libperl.so.5.14(perl_destruct+0x1e2d)[0x7f3b8c21d97d] perl(main+0x111)[0x400eb1] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xfd)[0x7f3b8b7c8ead] perl[0x400f21] etc. SamuelThread Next