cargo xbuild doesn't take advantage of CARGO_TARGET_DIR

rust-osdev / cargo-xbuild

Automatically cross-compiles the sysroot crates core, compiler_builtins, and alloc.

Apache License 2.0

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cargo xbuild doesn't take advantage of CARGO_TARGET_DIR #36

Open alex opened 5 years ago

alex commented 5 years ago

I'm not sure exactly how this plays out, but I compile a number of crates using cargo xbuild, and I try to set CARGO_TARGET_DIR so that they all share a target/ directory and I only need to build the various dependencies once. However, core, compiler_builtins, and alloc seem to get rebuilt every time.

You can see this in the travis output for any build on https://travis-ci.org/alex/linux-kernel-module-rust

phil-opp commented 5 years ago

You could try setting the XBUILD_SYSROOT_PATH environment variable.

I agree that it might make sense to consider the CARGO_TARGET_DIR environment variable too for placing the sysroot. However, there are some problems with using the same sysroot for mulitple independent projects due to some internal checksums, if I remember correctly.