When rustc prints an error containing a long type that doesn't fit in a
line, it will write the whole thing in a .txt file and print messages
like:
note: the full type name has been written to
'path/to/subsystem/module_name.long-type-11621316855315349594.txt'
[ Depending on the compiler version and the kind of error, there are
two possible spellings -- copying them here for reference:
= note: the full name for the type has been written to '...long-type-...txt'
= note: the full type name has been written to '...long-type-...txt'
In addition, we could clean the files as well in one of our
cleaning Make targets [1][2].
Another option would be `--verbose` (but it implies more things
that we probably don't want) or `-Zwrite-long-types-to-disk=no`
(unstable so far, but a possible alternative if we prefer to
avoid the files and simply see the long types in the output
-- I asked upstream Rust about it [3]).
Long types like core::result::Result<core::pin::Pin<Box<_, Kmalloc,
kernel::error::Error>: pin_init::PinInit<Box<_, Kmalloc>, _> are common
during development, so add a gitignore entry.