Well, it seems to be working for my local setup without any additional preparation.
You could try and see if the links were created in
./usr/bin/ccache in the MXE Octave build tree.
ccache.conf contains the following:
max_size = 80.0G
hash_dir = false
compiler_check = %compiler% -v
I don’t remember now why exactly I added
hash_dir = false. I believe I intended to make the cache match for multiple MXE trees with similar configuration.
The ccache documentation has the following to say about it:
hash_dir ( CCACHE_HASHDIR or CCACHE_NOHASHDIR , see Boolean values above)
If true (which is the default), ccache will include the current working directory (CWD) in the hash that is used to distinguish two compilations when generating debug info (compiler option -g with variations). Exception: The CWD will not be included in the hash if base_dir is set (and matches the CWD) and the compiler option -fdebug-prefix-map is used. See also the discussion under COMPILING IN DIFFERENT DIRECTORIES.
The reason for including the CWD in the hash by default is to prevent a problem with the storage of the current working directory in the debug info of an object file, which can lead ccache to return a cached object file that has the working directory in the debug info set incorrectly.
You can disable this option to get cache hits when compiling the same source code in different directories if you don’t mind that CWD in the debug info might be incorrect.
Is the cwd different for each run?
Maybe it is worth trying with that setting?