7 In order to see what ccache is doing, it is possible to enable internal
10 * Build ccache with the `-DENABLE_TRACING=1` cmake option.
11 * Set the environment variable `CCACHE_INTERNAL_TRACE` to instruct ccache to
12 create trace files at runtime.
14 There will be one trace file per ccache invocation, named as the object file
15 with a `.ccache-trace` suffix, e.g. `file.o.ccache-trace`. The trace file can
16 then be loaded into the `chrome://tracing` page of Chromium/Chrome.
18 You can combine several trace files into by using the `misc/combine-trace-files`
21 misc/combine-trace-files *.o.ccache-trace | gzip > ccache.trace.gz
23 (The gzip step is optional; Chrome supports both plain trace files and gzipped
24 trace files.) The script will offset each individual trace by its start time in
27 There is also a script called `summarize-trace-files` that generates a summary
28 (per job slot) of all the ccache runs:
30 misc/combine-trace-files *.o.ccache-trace | misc/summarize-trace-files 4 > ccache.trace
32 The script takes the number of job slots you used when building (e.g. `4` for
33 `make -j4`) as the first argument.