2 files changed, 17 insertions, 2 deletions
@@ -191,6 +191,13 @@ config BR2_CCACHE
up future builds. The cache is stored in
+ Note that Buildroot does not try to invalidate the cache
+ contents when the compiler changes in an incompatible
+ way. Therefore, if you make a change to the compiler version
+ and/or configuration, you are responsible for purging the
+ ccache cache by removing the $HOME/.buildroot-ccache
bool "Show packages that are deprecated or obsolete"
diff --git a/package/ccache/ccache.mk b/package/ccache/ccache.mk
index 393989f546..f71376ee85 100644
@@ -25,10 +25,18 @@ HOST_CCACHE_CONF_ENV = \
# has zero dependency besides the C library.
HOST_CCACHE_CONF_OPT += ccache_cv_zlib_1_2_3=no
-# We directly hardcode the cache location into the binary, as it is
-# much easier to handle than passing an environment variable.
+# We directly hardcode configuration into the binary, as it is much
+# easier to handle than passing an environment variable. Our
+# configuration is:
+# - the cache location
+# - the fact that ccache shouldn't use the compiler binary mtime to
+# - detect a change in the compiler, because in the context of
+# - Buildroot, that completely defeats the purpose of ccache. Of
+# - course, that leaves the user responsible for purging its cache
+# - when the compiler changes.
sed -i 's,getenv("CCACHE_DIR"),"$(CCACHE_CACHE_DIR)",' $(@D)/ccache.c
+ sed -i 's,getenv("CCACHE_COMPILERCHECK"),"none",' $(@D)/ccache.c
HOST_CCACHE_POST_CONFIGURE_HOOKS += \