[ccache] ccache version 3.4.2 has been released

[Joel Rosdahl]

ccache version 3.4.2 is now available.

Details may be read in the release notes:

    http://ccache.samba.org/releasenotes.html#_ccache_3_4_2

Source archives are available here:

    https://www.samba.org/ftp/ccache/ccache-3.4.2.tar.bz2
    https://www.samba.org/ftp/ccache/ccache-3.4.2.tar.gz
    https://www.samba.org/ftp/ccache/ccache-3.4.2.tar.xz

The source archives have been signed with my OpenPGP key (ID 5594ADB8,
fingerprint 5A93 9A71 A467 92CF 5786 6A51 996D DA07 5594 ADB8):

    https://www.samba.org/ftp/ccache/ccache-3.4.2.tar.bz2.asc
    https://www.samba.org/ftp/ccache/ccache-3.4.2.tar.gz.asc
    https://www.samba.org/ftp/ccache/ccache-3.4.2.tar.xz.asc

You can run "gpg --verify ccache-3.4.2.tar.*.asc" to check the source
archive integrity after download.

Bug fixes:

- The cleanup algorithm has been fixed to not misbehave when files are
  removed by another process while the cleanup process is running.
  Previously, too many files could be removed from the cache if multiple
  cleanup processes were triggered at the same time, in extreme cases
  trimming the cache to a much smaller size than the configured limits.

- Correctly hash preprocessed headers located in a ".gch directory".
  Previously, ccache would not pick up changes to such precompiled
  headers, risking false positive cache hits.

- Fixed build failure when using the bundled zlib sources.

- ccache 3.3.5 added a workaround for not triggering Clang errors when a
  precompiled header's dependency has an updated timestamp (but
  identical content). That workaround is now only applied when the
  compiler is Clang.

- Made it possible to perform out-of-source builds in dev mode again.

-- Joel