With this week, the build got unstable, i.e. it fails in pdump about half the time. It seems to be this patch: changeset: 6352:e02d10a9c9c8 user: Aidan Kehoe <kehoea(a)parhasard.net&gt; date: Thu Nov 23 06:27:49 2017 +0000 summary: Fix some mmap() compatibility problems on OSX. Here's the backtrace: * thread #1: tid = 0x0000, 0x00000001000a9d35 temacs`pdump_store_new_pointer_offsets(count=<unavailable>, data=0x0000000101d5d000, orig_data=0x0000000101909820, desc=<unavailable>, size=40) + 837 at dumper.c:1123, stop reason = signal SIGSTOP * frame #0: 0x00000001000a9d35 temacs`pdump_store_new_pointer_offsets(count=<unavailable>, data=0x0000000101d5d000, orig_data=0x0000000101909820, desc=<unavailable>, size=40) + 837 at dumper.c:1123 [opt] frame #1: 0x00000001000a7e42 temacs`pdump_dump_data(elt=<unavailable>, desc=0x000000010030ef10) + 82 at dumper.c:1223 [opt] frame #2: 0x00000001000a7a3e temacs`pdump_scan_by_alignment(f=(temacs`pdump_dump_data at dumper.c:1214), g=(temacs`pdump_dump_cv_data at dumper.c:1580), h=(temacs`pdump_dump_cv_ptr at dumper.c:1586)) + 126 at dumper.c:1654 [opt] frame #3: 0x00000001000a67d1 temacs`pdump + 2769 at dumper.c:2165 [opt] frame #4: 0x000000010007988a temacs`Fdump_emacs(filename=<unavailable>, symfile=<unavailable>) + 266 at emacs.c:3334 [opt] [...]