Mercurial > hg-stable
view rust/README.rst @ 43918:a89381e04c58
procutil: try and avoid angering CoreFoundation on macOS
We've seen failures like this:
objc[57662]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called.
objc[57662]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
I think this is due to forking off some background processes during
`hg update` or similar. I don't have any conclusive proof this is the
fork() call that's to blame, but it's the most likely one since the
regular `hg update` codepath uses the other fork() invocation (via
workers) and we don't get this report from non-Google macOS users.
Ugh.
Differential Revision: https://phab.mercurial-scm.org/D7615
author | Augie Fackler <augie@google.com> |
---|---|
date | Thu, 05 Dec 2019 16:19:16 -0500 |
parents | 964212780daf |
children | 8a3b045d9086 |
line wrap: on
line source
=================== Mercurial Rust Code =================== This directory contains various Rust code for the Mercurial project. The top-level ``Cargo.toml`` file defines a workspace containing all primary Mercurial crates. Building ======== To build the Rust components:: $ cargo build If you prefer a non-debug / release configuration:: $ cargo build --release Features -------- The following Cargo features are available: localdev (default) Produce files that work with an in-source-tree build. In this mode, the build finds and uses a ``python2.7`` binary from ``PATH``. The ``hg`` binary assumes it runs from ``rust/target/<target>hg`` and it finds Mercurial files at ``dirname($0)/../../../``. Build Mechanism --------------- The produced ``hg`` binary is *bound* to a CPython installation. The binary links against and loads a CPython library that is discovered at build time (by a ``build.rs`` Cargo build script). The Python standard library defined by this CPython installation is also used. Finding the appropriate CPython installation to use is done by the ``python27-sys`` crate's ``build.rs``. Its search order is:: 1. ``PYTHON_SYS_EXECUTABLE`` environment variable. 2. ``python`` executable on ``PATH`` 3. ``python2`` executable on ``PATH`` 4. ``python2.7`` executable on ``PATH`` Additional verification of the found Python will be performed by our ``build.rs`` to ensure it meets Mercurial's requirements. Details about the build-time configured Python are built into the produced ``hg`` binary. This means that a built ``hg`` binary is only suitable for a specific, well-defined role. These roles are controlled by Cargo features (see above). Running ======= The ``hgcli`` crate produces an ``hg`` binary. You can run this binary via ``cargo run``:: $ cargo run --manifest-path hgcli/Cargo.toml Or directly:: $ target/debug/hg $ target/release/hg You can also run the test harness with this binary:: $ ./run-tests.py --with-hg ../rust/target/debug/hg .. note:: Integration with the test harness is still preliminary. Remember to ``cargo build`` after changes because the test harness doesn't yet automatically build Rust code.