- Update to version 4.2.1:
* Ccache now only dup2`s stderr into `$UNCACHED_ERR_FD for calls to the preprocessor/compiler. This works around a complex bug in interaction with GNU Make, LTO linking and the Linux PTY driver.
* Fixed detection of color diagnostics usage when using -Xclang -fcolordiagnostics options.
* The -frecord-gcc-switches compiler option is now handled correctly to avoid false positive cache hits.
* Made it possible for per-compilation debug log files to be written in most argument processing error scenarios. Previously, ccache would only write debug log files if the argument processing phase was successful.
* Made ccache bail out on too hard Clang option -gen-cdb-fragment-path.
* The run_second_cpp made is now enforced on macOS if -g is used since newer Clang versions on macOS produce different debug information when compiling preprocessed code.
* Made ccache only reject -f(no-)color-diagnostics for a known GCC compiler. This fixes a problem when using said option with clang++ on macOS.
* Build configuration scripts now probe for atomic increment as well. This fixes a linking error on Sparc.
* An existing CMake log message level is now used when warning about not finding asciidoc.
* Fixed assertion in the "Debug option" test.
* Upgraded to doctest 2.4.6. This fixes a build error with glibc >= 2.34.