Building 1.6 from source, rustc complains crate core is from an older incompatible compiler?


I’m building 1.6 from the source tarball on the website. There are no prior rustc or rust/crate artifacts on the system (and on top of that, it is being built in a chroot). I am bootstrapping using rust-stage0-2015-08-11-1af31d4-linux-x86_64-*.tar.bz2, which the latest snapshot listed in src/snapshots.txt. The build ultimately fails when rustc attempts to compile src/liblibc/src/ saying:

src/liblibc/src/ 1:1 error: the crate `core` has been compiled with an old version of rustc, which is incompatible with this version of rustc [E0514]

How could this be the case if I’m building from source using the appropriate bootstrap compiler? Am I missing something really obvious here? I see earlier in the log it successfully builds libcore and touches stage1/lib/stamp.core. It was built using the same stage0 rustc being used later when the error occurs.


I think I found the root cause. I need to pass --sysroot to stage 0 because of being in a chroot jail with no /proc. I do this by passing it in RUSTFLAGS. It then gets carried over to each subsequent stage, which results in the stage 0 sysroot being passed to the stage 1 rustc.

Now I just need to figure out how to pass a different sysroot for each stage N of the build…


Can’t you just put the tarball in a directory named dl and let the build system work it out?

IIRC that was the cache directory for the downloads.


Building 1.6 from source

There is not enough Counter Strike jokes in this community…

(sorry for offtopic)


In case anyone else ever runs into this issue, I’ve noted what you need in order to build in a chroot here: