Metamode

Metamode is an incremental build system for FreeBSD, which uses bmake's meta mode and filemon(4) to create metadata files, substantially decreasing build times by only building what has changed since the last build.

Note: Enabling META_MODE also implies (enables) NO_CLEAN in the buildworld process

1. Add WITH_META_MODE=YES to /etc/src-env.conf
2. Run # kldload filemon
3. Run # make cleanworld once. If objects don't have .meta files then META_MODE won't do the right thing on an incremental build. ¹⁾
4. FreeBSD buildworld will now create meta files to improve the performance of future builds.

• Don't mix WITH_META_MODE with ccache(1) as mentioned in this thread .
  • For all versions from 12.0-RELEASE and going forward, both technologies work as expected.
• WITH_META_MODE is not the same thing as WITH_DIRDEPS_BUILD, which is an alternative, experimental build system.
  • Building FreeBSD in meta mode
  • Improving the FreeBSD Build (BSDCan 2016)
  • Description of meta mode in bmake(1)
  • Speeding up builds on FreeBSD

• src.conf(5)
• build(7)