bootstrap.py needs a lockfile to prevent concurrent invocations
@lolbinarycat is already working on this.
Since Jul 12, 2025.
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Description
Summary
cargo uses lockfiles to protect the build directory, however these only protect against parallel invocations of cargo, and bootstrap does a bunch of other file manipulations that
Command used
./x tidy & ./x tidy
Expected behaviour
One invocation acquires the lockfile, while the other blocks and waits for the lockfile to be unlocked, resuming once the first one is complete.
This is a problem because or rust-analyzer config recommends going through ./x check, which may cause build cache corruption if the user runs an ./x.py command at the same time r-a decides to do a check.
Actual behaviour
Both instances of bootstrap try to operate on the same files at the same time, causing one of them to crash.
Bootstrap configuration (bootstrap.toml)
profile = "tools" # Includes one of the default files in src/bootstrap/defaults
change-id = 138986
rust.debuginfo-level = 1
#rust.jemalloc = true
rust.download-rustc = false
rust.deny-warnings = false
build.docs-minification = false
#build.incremental = false
build.tidy-extra-checks = "auto:py"
Operating system
Arch Linux
HEAD
78a6e132984dba0303ebad7dcfd1305c93ad5835
Additional context
Build Log
extracting /home/binarycat/src/rs/rust/build/cache/2025-06-24/rustc-beta-x86_64-unknown-linux-gnu.tar.xz
extracting /home/binarycat/src/rs/rust/build/cache/2025-06-24/rust-std-beta-x86_64-unknown-linux-gnu.tar.xz
extracting /home/binarycat/src/rs/rust/build/cache/2025-06-24/cargo-beta-x86_64-unknown-linux-gnu.tar.xz
Traceback (most recent call last):
File "/home/binarycat/src/rs/rust/x.py", line 53, in <module>
bootstrap.main()
~~~~~~~~~~~~~~^^
File "/home/binarycat/src/rs/rust/src/bootstrap/bootstrap.py", line 1372, in main
bootstrap(args)
~~~~~~~~~^^^^^^
File "/home/binarycat/src/rs/rust/src/bootstrap/bootstrap.py", line 1337, in bootstrap
build.download_toolchain()
~~~~~~~~~~~~~~~~~~~~~~~~^^
File "/home/binarycat/src/rs/rust/src/bootstrap/bootstrap.py", line 696, in download_toolchain
shutil.rmtree(bootstrap_build_artifacts)
~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.13/shutil.py", line 763, in rmtree
_rmtree_safe_fd(stack, onexc)
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
File "/usr/lib/python3.13/shutil.py", line 704, in _rmtree_safe_fd
onexc(func, path, err)
~~~~~^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.13/shutil.py", line 658, in _rmtree_safe_fd
os.rmdir(name, dir_fd=dirfd)
~~~~~~~~^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: '/home/binarycat/src/rs/rust/build/bootstrap/debug'
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