Rustup installs 64bit compiler on a 32bit Docker instance

[shaleh]

This is what is in my dockerfile:

 RUN curl https://sh.rustup.rs -o rustup.sh && sh rustup.sh --default-toolchain nightly -y && rustup default nightly

Here are some details from the docker instance

root@cc25a7d3570a:~/test32# uname -a
 Linux cc25a7d3570a 4.4.0-97-generic #120-Ubuntu SMP Tue Sep 19 17:28:18 UTC 2017 i686 i686 i686 GNU/Linux
root@cc25a7d3570a:~/test32# rustc --version
rustc 1.23.0-nightly (2be4cc040 2017-11-01)
root@cc25a7d3570a:~/test32# rustup show
Default host: x86_64-unknown-linux-gnu

installed toolchains
--------------------

nightly-i686-unknown-linux-gnu (default)
nightly-x86_64-unknown-linux-gnu

active toolchain
----------------

nightly-i686-unknown-linux-gnu (default)
rustc 1.23.0-nightly (2be4cc040 2017-11-01)

I hand installed the i686 compiler by running rustup install nightly-i686-unknown-linux-gnu.

You can find the Dockerfile here

[shaleh]

The 32 bit Dockerfile can be seen here: https://github.com/Wilfred/remacs/blob/master/docker/ubuntu/32bit/Dockerfile

If I set the default-host explicitly with --default-host i686-unknown-linux-gnu then the right thing happens. If I leave it up to rustup-init determining the host I get a mixed i686 and x86_64 Rust install which refuses to run (as you might expect).

[kinnison]

I believe this has come up again, and we ought to see if we can fix it. cf. #2111

[kinnison]

I have investigated and I believe that this should be working with current rustup. Could you please double-check @shaleh and let me know. If it's not working, can you please add -x to the sh cmdline (i.e. sh -x rustup.sh ...) and paste from where it looks at /proc/self/exe to where it starts downloading the installer please?

[kinnison]

It is my strong belief that this is no longer a problem on x86, and with the patch for #2111 it'll be fixed for aarch64/armv7 too. If it is still an issue, please reopen with details as above.