The rust bootstrap downloads files into a "tmp" directory then moves the
files into the "cache" directory using std::fs::rename. There are no
issues in the original/unpatched case as "tmp" and "cache" are
subdirectories in the build directory ($(HOST_BUILD_DIR)/build) and so
are nearly guaranteed to be on the same filesystem.
35768bf31e changed where files are
saved/cached (in $(DL_DIR)/rustc). If HOST_BUILD_DIR and DL_DIR are on
separate filesystems, then using std::fs::rename to move the files will
fail.[1]
This updates 0002-rustc-bootstrap-cache.patch to account for this case,
i.e. if std::fs::rename fails, fall back to copying the file then
removing the original.
[1]: https://github.com/openwrt/packages/pull/22457
Fixes: 35768bf31e ("rust: Cache bootstrap downloads to $(DL_DIR)/rustc")
Signed-off-by: Jeffery To <jeffery.to@gmail.com>
(cherry picked from commit f9f1e0220f)
Tianling Shen