what have I done now?

err.log

$ RUST_LOG=rustc=0,::rt::backtrace make
cfg: shell host triple x86_64-unknown-linux-gnu
cfg: host for x86_64-unknown-linux-gnu is x86_64
cfg: unix-y environment
cfg: using gcc
cfg: no llnextgen found, omitting grammar-verification
compile_and_link: x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib/libstd.so
rust: upcall fail 'Assertion !ty::type_has_params(t) failed', /home/rustbuild/src/rustbot/workspace-snap-stage3-x86_64-unknown-linux-gnu/src/src/rustc/middle/trans/common.rs:929
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(_ZN9rust_task13begin_failureEPKcS1_m+0x55)[0x2b5e9c1faf65]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(+0x2fce9)[0x2b5e9c211ce9]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(upcall_fail+0x164)[0x2b5e9c1ff034]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans6common12node_id_type17_b99b7c2cd714a2cd3_02E+0x110)[0x2b5e9ba7bce0]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base13trans_closure17_e758ede6e6b3cc683_02E+0x2e7)[0x2b5e9baf9777]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base8trans_fn17_9c4f6b71fcb4ca153_02E+0x15c)[0x2b5e9bac9b1c]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_item17_c9a7adcac9f519d03_02E+0xf7b)[0x2b5e9bad353b]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_stmt17_86b5b12f68c12b913_02E+0x368)[0x2b5e9baf6058]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base11trans_block17_f572c6ab6e338fb53_02E+0x146)[0x2b5e9bac0066]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base13trans_closure17_e758ede6e6b3cc683_02E+0x4e7)[0x2b5e9baf9977]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base8trans_fn17_9c4f6b71fcb4ca153_02E+0x15c)[0x2b5e9bac9b1c]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base14monomorphic_fn17_93edbbc08330747d3_02E+0x26ac)[0x2b5e9baa90fc]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base20lval_static_fn_inner17_d23aff5b3b785a623_02E+0x16a)[0x2b5e9bad4fda]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base14lval_static_fn17_e15b4545781854343_02E+0x12e)[0x2b5e9bad4bce]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4impl19trans_method_callee17_d9c495df5a253b8a3_02E+0xf4)[0x2b5e9bab5be4]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base12trans_callee17_188ac9d0f1731ee73_02E+0x1f1)[0x2b5e9badb471]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0xfa754)[0x2b5e9bae8754]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10with_scope17_e6a6bc22e0527aca3_02E+0xae)[0x2b5e9bae853e]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_call17_fc212eb371a61c503_02E+0x28b)[0x2b5e9bae4c5b]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0xfe5ff)[0x2b5e9baec5ff]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0x3facbc)[0x2b5e9bde8cbc]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_expr17_db2a22b634d8b5df3_02E+0x6de)[0x2b5e9bab654e]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_stmt17_86b5b12f68c12b913_02E+0x30c)[0x2b5e9baf5ffc]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base11trans_block17_f572c6ab6e338fb53_02E+0x146)[0x2b5e9bac0066]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans3alt15trans_alt_inner17_e28394a0cbe3244e3_02E+0xc3e)[0x2b5e9bb25fde]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0x13738c)[0x2b5e9bb2538c]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10with_scope17_e6a6bc22e0527aca3_02E+0xae)[0x2b5e9bae853e]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans3alt9trans_alt17_dcdeeabdabdd91973_02E+0x1d8)[0x2b5e9baefbd8]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0xfe818)[0x2b5e9baec818]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_expr17_db2a22b634d8b5df3_02E+0x6de)[0x2b5e9bab654e]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_stmt17_86b5b12f68c12b913_02E+0x30c)[0x2b5e9baf5ffc]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base11trans_block17_f572c6ab6e338fb53_02E+0x146)[0x2b5e9bac0066]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base11trans_while17_77b8f720b0a5c15a3_02E+0x547)[0x2b5e9bac08b7]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0x100501)[0x2b5e9baee501]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0x3facbc)[0x2b5e9bde8cbc]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_expr17_db2a22b634d8b5df3_02E+0x6de)[0x2b5e9bab654e]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_stmt17_86b5b12f68c12b913_02E+0x30c)[0x2b5e9baf5ffc]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base11trans_block17_f572c6ab6e338fb53_02E+0x146)[0x2b5e9bac0066]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base13trans_closure17_e758ede6e6b3cc683_02E+0x4e7)[0x2b5e9baf9977]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base8trans_fn17_9c4f6b71fcb4ca153_02E+0x15c)[0x2b5e9bac9b1c]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0x14249e)[0x2b5e9bb3049e]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4impl10trans_impl17_aae19287c42f34123_02E+0x257)[0x2b5e9bb00007]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_item17_c9a7adcac9f519d03_02E+0xd6b)[0x2b5e9bad332b]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base9trans_mod17_4c3b3327d499ade83_02E+0xa8)[0x2b5e9bb00218]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base10trans_item17_c9a7adcac9f519d03_02E+0x3e7)[0x2b5e9bad29a7]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base9trans_mod17_4c3b3327d499ade83_02E+0xa8)[0x2b5e9bb00218]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6middle5trans4base11trans_crate17_77d1c582fe13d22a3_02E+0x1170)[0x2b5e9bb0e080]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0x3facbc)[0x2b5e9bde8cbc]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6driver6driver12compile_upto17_a0439d1a618f982b3_02E+0x2ca8)[0x2b5e9bdcd618]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(+0x3facbc)[0x2b5e9bde8cbc]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustc-73389320c1332876-0.2.so(_ZN6driver6driver13compile_input17_1fd9faf12ff445bd3_02E+0xbb)[0x2b5e9bdd236b]
x86_64-unknown-linux-gnu/stage0/bin/rustc[0x4073f9]
x86_64-unknown-linux-gnu/stage0/bin/rustc[0x40b7bc]
x86_64-unknown-linux-gnu/stage0/bin/rustc[0x40ac1e]
x86_64-unknown-linux-gnu/stage0/bin/rustc[0x40a858]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(+0x36bf5)[0x2b5e9a877bf5]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(_Z18task_start_wrapperP10spawn_args+0x2b)[0x2b5e9c1fc0ab]
error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug
note: try running with RUST_LOG=rustc=0,::rt::backtrace to get further details and report the results to github.com/mozilla/rust/issues
rust: upcall fail 'explicit failure', /home/rustbuild/src/rustbot/workspace-snap-stage3-x86_64-unknown-linux-gnu/src/src/rustc/driver/rustc.rs:254
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(_ZN9rust_task13begin_failureEPKcS1_m+0x55)[0x2b5e9c1faf65]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(+0x2fce9)[0x2b5e9c211ce9]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(upcall_fail+0x164)[0x2b5e9c1ff034]
x86_64-unknown-linux-gnu/stage0/bin/rustc[0x40a096]
x86_64-unknown-linux-gnu/stage0/bin/rustc[0x40b7bc]
x86_64-unknown-linux-gnu/stage0/bin/rustc[0x40b147]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(_Z18task_start_wrapperP10spawn_args+0x2b)[0x2b5e9c1fc0ab]
rust: domain main @0x1caaec0 root task failed
rust: upcall fail 'killed', /home/rustbuild/src/rustbot/workspace-snap-stage3-x86_64-unknown-linux-gnu/src/src/libcore/task.rs:454
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(_ZN9rust_task13begin_failureEPKcS1_m+0x55)[0x2b5e9c1faf65]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(+0x2fce9)[0x2b5e9c211ce9]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(upcall_fail+0x164)[0x2b5e9c1ff034]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(_ZN4task5yield17_8bfde8cf2fff81633_02E+0xd1)[0x2b5e9a876121]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(+0x46b94)[0x2b5e9a887b94]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(_ZN4priv11weaken_task17_202347307ab73eb23_02E+0xbf)[0x2b5e9a887a1f]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(+0x59644)[0x2b5e9a89a644]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(+0x468e6)[0x2b5e9a8878e6]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(+0x4620f)[0x2b5e9a88720f]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(+0x45e45)[0x2b5e9a886e45]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(+0x36bf5)[0x2b5e9a877bf5]
/code/rust/x86_64-unknown-linux-gnu/stage0/bin/../lib/librustrt.so(_Z18task_start_wrapperP10spawn_args+0x2b)[0x2b5e9c1fc0ab]
make: *** [x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib/libstd.so] Error 101