Sometimes when hacking on Quantum Render, you'll need to make a change to one of the upstream dependencies of the webrender library (say for example [https://github.com/servo/euclid euclid]). However, you may need to test out your changes in the QR build. The way to do this is not obvious, because the QR build uses the vendored copy of euclid (in third_party/rust/euclid) which you can't directly modify without violating the checksum checks. Instead, what you need to do is this:
* First we make a copy of the vendored euclid repo cd In $MOZILLA_ROOT/third_party/rust cp -R euclid euclid_modified* Then, make your desired changes to euclid_modified.* Then, we need to tell the build system to use euclid_modified instead of euclid. Note that for this to work, the version numbers in the Cargo.toml files , there should be the same in euclid and euclid_modified. The following steps add a [replace] section to at the topbottom called [patch.crates-level libgkrust Cargoio].toml file to use the modified euclid. See httpAdd an entry like so://doc [patch.crates.-io/manifest].html#the-replace-section for details. You'll need to replace the <tt>0.10.3</tt> in the command below with whatever the library version in (as of this writing euclid is at v0.10.3 in the graphics repo). cd $MOZILLA_ROOT/toolkit/library/rust/ echo -e '[replace]\n"euclid:0.10.3" = { path = "../../../third_party/rust/euclid_modifiedeuclid" }" >> Cargo.toml cargo update -p euclid # This updates CargoThen run .lock* And then build with your modified euclid: cd $MOZILLA_ROOT /mach buildvendor rust
== Hacking ==
