As for this very moment, I am unable to build mail-client/thunderbird-68.1.1 on fully updated ~amd64 system. dev-lang/rust-1.38.0 sys-devel/gcc-9.2.0-r1 sys-devel/llvm-9.0.0 1G 2:28.55 error[E0506]: cannot assign to `self.input.cached_token` because it is borrowed 1G 2:28.55 --> /var/portage/tmp/portage/mail-client/thunderbird-68.1.1/work/thunderbird-68.1.1/third_party/rust/cssparser/src/parser.rs:584:17 1G 2:28.55 | 1G 2:28.55 559 | pub fn next_including_whitespace_and_comments(&mut self) -> Result<&Token<'i>, BasicParseError<'i>> { 1G 2:28.55 | - let's call the lifetime of this reference `'1` 1G 2:28.55 ... 1G 2:28.55 572 | Some(ref cached_token) 1G 2:28.55 | ---------------- borrow of `self.input.cached_token` occurs here 1G 2:28.55 ... 1G 2:28.55 584 | self.input.cached_token = Some(CachedToken { 1G 2:28.55 | ^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.input.cached_token` occurs here 1G 2:28.55 ... 1G 2:28.55 596 | Ok(token) 1G 2:28.55 | --------- returning this value requires that `self.input.cached_token.0` is borrowed for `'1` 1G 2:28.77 error: aborting due to previous error 1G 2:28.77 For more information about this error, try `rustc --explain E0506`. 1G 2:28.79 error: Could not compile `cssparser`. 1G 2:28.79 warning: build failed, waiting for other jobs to finish...
Bug 695794 is about the same error and comes with a patch. Apparently this has been fixed in servo/rust-cssparser versions v0.25.5..v0.25.9(current) but thunderbird-68.1.1 uses version 0.25.3.
*** This bug has been marked as a duplicate of bug 695794 ***
