ICE in recent rustc version

[dhardy]

I don't know whether this was already reported. I get an ICE when running cargo test on this Pippin version (also the previous commit, didn't test others).

Compiler output

dhardy@localhost:~/other/pippin$ cargo --version && rustc --version
cargo 0.11.0-nightly (afac7fc 2016-04-27)
rustc 1.10.0-nightly (8da2bcac5 2016-04-28)

An older version works fine:

dhardy@localhost:~/other/pippin$ cargo --version && rustc --version
cargo 0.10.0-nightly (4576ae2 2016-03-16)
rustc 1.9.0-nightly (6e0f2f2f0 2016-03-16)

[nagisa]

cc @eddyb has Callee in trace.

[eddyb]

My guess is Callee::trait_method or meth::get_impl_method needs to normalize the substitutions/TraitRef.

[vwim]

Getting the same ICE with rustc 1.10.0-nightly (b5ba5923f 2016-04-21) but also on rustc 1.9.0-beta while running https://github.com/sebcrozet/ncollide examples (works fine on 1.8.0).

[xen0n]

Just bisected this and got

There are only 'skip'ped commits left to test.
The first bad commit could be any of:
7011e30352583b5965c4a9118ca2c14b8ab24454
55b5a365ef64c6c1a53e348a5a5a5ff1cac1d958
9221b9118b96d668e2cf5d701b10c0566aa072e9
5af3c12cfc07887b66ed1d8cd9e59e1c77cc8790
c6d214bdeb1bfc9664ad14085c94bf2cbc5af6ee
b122d1636ac502dad51c827c16dc95d80d96c838
c3f856e7e24be568902a38c6a488aee6098f94cc
89766a81ef6270595cb8e51f100ed44be4bb9929
e0970498c79de1a1381d697b3c27895ef798e288
16201d45f16845cb5dc2fc0b48bcf34a6715ea14
d6e72c48dd7dacebe08b44e7ee6ce0f052797f55
062a05dde8c3ea5386fa358d882e1eaca99a9ff0
b05556e06da7c79f9db746728c2557114a94b3b1
b918e37eb3e393c5a5b0408430e146c0b66ec7ed
cdfad40735745252ad42519df8a6c8ecc3739b58
da66431d06b961efd323f25978964df54d44d3c4
We cannot bisect more!

Surely it regressed during the trans refactoring, but as none of the intermediate commits is building it's not exactly sure which change is to blame though. Will help investigating further.

[xen0n]

I would try to fix this, already did one-liner fix in trans/callee.rs according to @eddyb , both pippin and the minimal testcase in #33461 passed without ICE. Will prepare the PR later ;-)

(EDIT: It's with stage1. Currently building stage2 and seeing if it can pass all tests. New to compiler writing and maintenance so kindly point out anything you feel like, thanks.)