`./x.py install` panics on a fresh clone

[ojeda]

Since commit bbdc7c4 ("bootstrap: Don't clone submodules unconditionally in dry-run"), this panics:

git clone https://github.com/rust-lang/rust && cd rust && ./configure && ./x.py install

with:

thread 'main' panicked at src/bootstrap/src/lib.rs:1683:20:
fs::read_to_string(toml_file_name) failed with No such file or directory (os error 2)

But this does not:

git clone https://github.com/rust-lang/rust && cd rust && ./configure && ./x.py build

The reason is that the Cargo submodule is not ready early enough.

This affects tools like tc-build: ClangBuiltLinux/tc-build#336 (originally reported by @nathanchance).

Cc @jyn514 @jieyouxu

[jyn514]

@ojeda do you have a backtrace available for this failure?

[jyn514]

ah don't worry about it, the only place it could be is src/bootstrap/src/utils/tarball.rs:100.

i'm surprised that x install --dry-run didn't catch this ... maybe i forgot to test it. i'll write up a fix tomorrow, should be pretty simple.

[jyn514]

oh i see, it requires setting build.extended = true.

[ojeda]

Thanks a lot @jyn514, that was quick! Yeah, that was it (and yeah, we use extended via dist -- I should have added the log).

I checked that after the PR landed, the reproducer here is fixed.

I also checked that tc-build works again now.

Closing our downstream issue.