On my Linux i7-6700K machine, `mach build` with artifacts takes ~52s (with the binary archive already downloaded). During the export tier, we have 2 long tails: WebIDL and IPDL processing. IPDL appears to be the slightly longer tail, taking ~9.4s to run. I really don't think we need to be processing IPDL files when we're not doing C++ foo. This should make artifact builds a bit faster.

IPDL processing takes ~9.4s on my i7-6700K and is the long pole in the "export" tier for clobber --disable-compile-environment builds. IPDL shouldn't be needed for these builds. Disabling IPDL makes artifact builds ~4s faster on my machine. Review commit: https://reviewboard.mozilla.org/r/30629/diff/#index_header See other reviews: https://reviewboard.mozilla.org/r/30629/

Comment on attachment 8707290 [details] MozReview Request: Bug 1239207 - Don't process IPDL when not compiling; r=glandium https://reviewboard.mozilla.org/r/30629/#review27829 ::: ipc/ipdl/Makefile.in:14 (Diff revision 1) > +ifdef COMPILE_ENVIRONMENT Might as well move this above the ipdlsrcs.mk include.

Comment on attachment 8707290 [details] MozReview Request: Bug 1239207 - Don't process IPDL when not compiling; r=glandium Review request updated; see interdiff: https://reviewboard.mozilla.org/r/30629/diff/1-2/