Win64, m-c, optimized build. I can see: 6:35.17 jsapi-tests.exe 7:14.77 Compiling geckoservo v0.0.1 (file:///C:/Mozilla/src/mozilla-central2/servo/ports/geckolib) 8:36.50 note: link against the following native artifacts when linking against this static library 8:36.50 8:36.50 note: the order and any duplication can be significant on some platforms, and so may need to be preserved 8:36.50 8:36.50 note: library: advapi32 8:36.50 8:36.50 note: library: kernel32 8:36.50 8:36.50 note: library: advapi32 8:36.50 8:36.50 note: library: ws2_32 8:36.50 8:36.51 note: library: userenv 8:36.51 8:36.51 note: library: shell32 8:36.51 8:36.51 note: library: msvcrt 8:36.51 8:37.25 Compiling gkrust-shared v0.1.0 (file:///C:/Mozilla/src/mozilla-central2/toolkit/library/rust/shared) 8:38.25 Compiling gkrust v0.1.0 (file:///C:/Mozilla/src/mozilla-central2/toolkit/library/rust) 12:01.47 note: link against the following native artifacts when linking against this static library 12:01.47 12:01.47 note: the order and any duplication can be significant on some platforms, and so may need to be preserved 12:01.47 12:01.47 note: library: advapi32 12:01.47 12:01.47 note: library: gdi32 12:01.47 12:01.47 note: library: kernel32 12:01.47 12:01.47 note: library: advapi32 12:01.47 12:01.47 note: library: ws2_32 12:01.47 12:01.47 note: library: userenv 12:01.47 12:01.47 note: library: shell32 12:01.47 12:01.47 note: library: msvcrt 12:01.47 12:01.54 Finished release [optimized] target(s) in 674.34 secs 12:01.61 xul_s.lib.desc 12:01.61 xul.dll while there is always only one rustc process running at the time. could this be parallelized?

Possibly a dupe of bug 1353472?