Best Ccache options for Xcode compiling

[adamivancza]

I have the following options set for ccache settings for our react-native iOS project:

  export CCACHE_MAXSIZE=10G
  export CCACHE_CPP2=true
  export CCACHE_DIR=~/ccache
  export CCACHE_SLOPPINESS=pch_defines,time_macros,file_macro,include_file_mtime,include_file_ctime,file_stat_matches,modules,clang_index_store,system_headers,ivfsoverlay
  export CCACHE_DEPEND=true
  export CCACHE_FILECLONE=true
  export CCACHE_INODECACHE=true
  export CCACHE_COMPILERCHECK=content

but our cache hit ratio is still relatively small:

Cacheable calls:    13020 / 13054 (99.74%)
  Hits:              3254 / 13020 (24.99%)
    Direct:          3254 /  3254 (100.0%)
    Preprocessed:       0 /  3254 ( 0.00%)
  Misses:            9766 / 13020 (75.01%)
Uncacheable calls:     34 / 13054 ( 0.26%)
Local storage:
  Cache size (GiB):   2.1 /   5.0 (42.39%)
  Hits:              3254 / 13020 (24.99%)
  Misses:            9766 / 13020 (75.01%)

Any suggestions what options should I change to improve the cache hit ratio? There was 0 native changes between when the cache was generated and between the build that produced the above cache hit ratios.

[jrosdahl]

To find out why you don't get hits I suggest following the hint at the end of Cache debugging in the manual.