Add the canonical header flag to gcc when compiling non-SYCL C++. This
flag is required to ensure that gcc will report the dependencies using
the directories provided by bazel, whereas by default gcc will use
a relative or absolute path depending on which is shortest. In general
this does not cause a problem, as the bazel cache has a fairly long
name and so the relative path is almost always shorter than the absolute
path, however this might not be the case when you change the location of
the bazel cache.
Add the canonical header flag to gcc when compiling non-SYCL C++. This flag is required to ensure that gcc will report the dependencies using the directories provided by bazel, whereas by default gcc will use a relative or absolute path depending on which is shortest. In general this does not cause a problem, as the bazel cache has a fairly long name and so the relative path is almost always shorter than the absolute path, however this might not be the case when you change the location of the bazel cache.
Regession introduced: bfaac96 Fixes: #215 See also: https://github.com/bazelbuild/bazel/issues/1642