rustbuild: stdlib not installed for 2nd target triple

[xi2]

Hi. I am testing out rust 1.15.0 beta and I came across a problem installing from source:

OS

Debian GNU/Linux 8 x86_64

Rust version

10893a9 (1.15.0-beta.5)

Actions

$ ./configure \
    --prefix=$HOME/rust \
    --enable-local-rust \
    --local-rust-root=$SNAPSHOT \
    --disable-rpath \
    --disable-manage-submodules \
    --target=x86_64-unknown-linux-gnu,i686-unknown-linux-gnu \
    --enable-vendor \
    --release-channel=beta
$ make
$ make install

Expected outcome

x86_64-unknown-linux-gnu and i686-unknown-linux-gnu directories in $HOME/rust/lib/rustlib.

Actual outcome

Only the x86_64-unknown-linux-gnu directory is present.

I am new to rust (just a couple of days) so forgive me if I've overlooked something. I'm pretty sure I installed 1.14.0 similarly and i686-unknown-linux-gnu was installed OK. That was using the old makefiles-based build system.

[alexcrichton]

IIRC this hasn't ever worked, but would be a great bug to fix with rustbuild!

[sezaru]

I've made a fix to this issue, you just need to apply this patch:

diff -ruN rustc-1.15.1-src/src/bootstrap/install.rs rustc-1.15.1-src_new/src/bootstrap/install.rs
--- rustc-1.15.1-src/src/bootstrap/install.rs	2017-02-09 01:37:48.000000000 +0000
+++ rustc-1.15.1-src_new/src/bootstrap/install.rs	2017-03-11 02:06:21.676817872 +0000
@@ -37,6 +37,12 @@
         install_sh(&build, "docs", "rust-docs", stage, host, prefix,
                    &docdir, &libdir, &mandir, &empty_dir);
     }
+    
+    for target in build.config.target.iter().filter(|target| *target != host) {
+        install_sh(&build, "std", "rust-std", stage, target, prefix,
+                   &docdir, &libdir, &mandir, &empty_dir);
+    }
+
     install_sh(&build, "std", "rust-std", stage, host, prefix,
                &docdir, &libdir, &mandir, &empty_dir);
     install_sh(&build, "rustc", "rustc", stage, host, prefix,

This will check the build structure for the targets provided on the configure stage, it will then remove any target that is equal to the host (since the host rustlibs will already be installed) and call the install function on it resulting in the installation of all the rustlibs for all the targets.

I don't know if this is the best approach or if there is some case that will fail and I'm not aware.

But, if it is a ok patch, can we apply it to the next version of rust since it seems that this is a major problem for a lot of users (at least for me it is since I'm trying to make the rust ebuild for gentoo support multiple targets and this bug is just what is preventing me).

Thanks

[alexcrichton]

@sezaru looks like a great start to me, you're more than welcome to send a PR!

I think that we'llalso want to update step.rs for the new dependencies, but other than that look great to me.