ccache not working on OS X/macOS

[koffes]

I discovered that ccache is not working with Zephyr SDK 0.17.0 on macOS.
Let me know if I should file this ticket elsewhere.

From the log below, ccache is installed, and is found, but there are no hits:

Cacheable calls:               0 / 1258 ( 0.00%)
  Hits:                        0
    Direct:                    0
    Preprocessed:              0
  Misses:                      0
Uncacheable calls:          1258 / 1258 (100.0%)
  Bad compiler arguments:    756 / 1258 (60.10%)
  Called for linking:        256 / 1258 (20.35%)
  Called for preprocessing:  124 / 1258 ( 9.86%)
  No input file:             122 / 1258 ( 9.70%)
Successful lookups:
  Direct:                      0
  Preprocessed:                0
Local storage:
  Cache size (GiB):          0.0 /  5.0 ( 0.00%)
  Files:                       0
  Hits:                        0
  Misses:                      0
  Reads:                       0

Another colleague of mine, noticed the same thing on a different macOS setup. He claimed that this may have happened with the transition to sysbuild.

Tested on:
Sequoia 15.0.1
SDK 0.17.0
Zephyr bleeding edge today (d3a0e16)
samples/basic/blinky can be used to test

When I get more time, I will bisect and find when this broke. I will also try different SDK versions.

[kartben]

@koffes can you try:

export CCACHE_IGNOREOPTIONS="-specs=* --specs=*"

I think we basically need to set this as a default somewhere
cc @nashif @tejlmand

[koffes]

Ah! Thank you @kartben ! That worked like a charm. Roughly 3X speedup.
As you said, this would be nice to set to default if possible. Will keep issue open.

[koffes]

I tried this on Windows as well, and setting the same env. var was required there.

[keith-packard]

Can anyone explain why this is needed? Seems like the --specs option should be the same in all compiles?

[kartben]

Can anyone explain why this is needed? Seems like the --specs option should be the same in all compiles?

@keith-packard
https://github.com/zephyrproject-rtos/zephyr/blob/main/.github%2Fworkflows%2Fcodecov.yaml#L36

Does that help?
If there is a way to fix this (maybe by providing full path to the specs file? https://stackoverflow.com/a/77878905/1051634) it would be nice :)

[keith-packard]

For the SDK, we could provide the full path to the specs file. Annoying that ccache doesn't search the library path specified by the compiler. I just tried 'arm-none-eabi-gcc -print-file-name=picolibc.specs' and that happily provided me the full path name.