Unwrap causes build to fail

[mgattozzi]

My builds started failing today what's weird is that it seems to be failing while downloading tokio-core, but not other codebases I have. I don't think this is related to #3833, but I'm not sure.

For reference the version of rust is:

rustc 1.17.0-nightly (a559452b0 2017-03-17)

Here's the full stack trace for reference.

cargo build               
 Downloading tokio-core v0.1.6
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', /checkout/src/libcore/option.rs:323
stack backtrace:
   0:     0x563790e16ac3 - std::sys::imp::backtrace::tracing::imp::unwind_backtrace::hf9ed9ccfd9f14c2b
                               at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1:     0x563790e12df4 - std::sys_common::backtrace::_print::hd8a1b72dcf3955ef
                               at /checkout/src/libstd/sys_common/backtrace.rs:71
   2:     0x563790e1e6bc - std::panicking::default_hook::{{closure}}::h5ff605bba7612658
                               at /checkout/src/libstd/sys_common/backtrace.rs:60
                               at /checkout/src/libstd/panicking.rs:355
   3:     0x563790e1e284 - std::panicking::default_hook::h9bc4f6dfee57d6bd
                               at /checkout/src/libstd/panicking.rs:371
   4:     0x563790e1eb0b - std::panicking::rust_panic_with_hook::hdc01585dc2bf7122
                               at /checkout/src/libstd/panicking.rs:549
   5:     0x563790e1e9e4 - std::panicking::begin_panic::hf84f4975d9f9b642
                               at /checkout/src/libstd/panicking.rs:511
   6:     0x563790e1e919 - std::panicking::begin_panic_fmt::hcc3f360b2ba80419
                               at /checkout/src/libstd/panicking.rs:495
   7:     0x563790e1e8a7 - rust_begin_unwind
                               at /checkout/src/libstd/panicking.rs:471
   8:     0x563790e4b01d - core::panicking::panic_fmt::h795d9a9608ddc2bb
                               at /checkout/src/libcore/panicking.rs:69
   9:     0x563790e4af54 - core::panicking::panic::hcab3e0dfa81beee9
                               at /checkout/src/libcore/panicking.rs:49
  10:     0x563790acd6de - cargo::version::haea7e89a3b191e3c

If this is actually tokio related I'll open up the issue there instead but since it panicked in the middle of downloading I thought it was actually a cargo issue.

[konstin]

I can reproduce this when adding e.g. reqwest = "0.4.0" to my cargo.toml. Everything works fine in old state, but cargo crashes after adding the dependency

[ms705]

I also encounter this issue (same nightly, Ubuntu 16.04), although in my case it happens on cargo update:

$ cargo update
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', /checkout/src/libcore/option.rs:323
stack backtrace:
   0:     0x55d09b35dac3 - std::sys::imp::backtrace::tracing::imp::unwind_backtrace::hf9ed9ccfd9f14c2b
                               at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1:     0x55d09b359df4 - std::sys_common::backtrace::_print::hd8a1b72dcf3955ef
                               at /checkout/src/libstd/sys_common/backtrace.rs:71
   2:     0x55d09b3656bc - std::panicking::default_hook::{{closure}}::h5ff605bba7612658
                               at /checkout/src/libstd/sys_common/backtrace.rs:60
                               at /checkout/src/libstd/panicking.rs:355
   3:     0x55d09b365284 - std::panicking::default_hook::h9bc4f6dfee57d6bd
                               at /checkout/src/libstd/panicking.rs:371
   4:     0x55d09b365b0b - std::panicking::rust_panic_with_hook::hdc01585dc2bf7122
                               at /checkout/src/libstd/panicking.rs:549
   5:     0x55d09b3659e4 - std::panicking::begin_panic::hf84f4975d9f9b642
                               at /checkout/src/libstd/panicking.rs:511
   6:     0x55d09b365919 - std::panicking::begin_panic_fmt::hcc3f360b2ba80419
                               at /checkout/src/libstd/panicking.rs:495
   7:     0x55d09b3658a7 - rust_begin_unwind
                               at /checkout/src/libstd/panicking.rs:471
   8:     0x55d09b39201d - core::panicking::panic_fmt::h795d9a9608ddc2bb
                               at /checkout/src/libcore/panicking.rs:69
   9:     0x55d09b391f54 - core::panicking::panic::hcab3e0dfa81beee9
                               at /checkout/src/libcore/panicking.rs:49
  10:     0x55d09b0146de - cargo::version::haea7e89a3b191e3c
                               at /checkout/src/libcore/macros.rs:21
                               at /checkout/cargo/src/cargo/lib.rs:263
  11:     0x55d09afa98cf - cargo::ops::registry::http_handle::h3e076e6b4e3144ec
                               at /checkout/cargo/src/cargo/ops/registry.rs:227
  12:     0x55d09afd2e19 - <cargo::sources::registry::remote::RemoteRegistry<'cfg> as cargo::sources::registry::RegistryData>::update_index::h282902cfa6380402
                               at /checkout/cargo/src/cargo/sources/registry/remote.rs:63
  13:     0x55d09afd86c7 - cargo::sources::registry::RegistrySource::do_update::h07f4b56389efd3cc
                               at /checkout/cargo/src/cargo/sources/registry/mod.rs:309
  14:     0x55d09afd8986 - <cargo::sources::registry::RegistrySource<'cfg> as cargo::core::source::Source>::update::h790227a7871fecb4
                               at /checkout/cargo/src/cargo/sources/registry/mod.rs:353
  15:     0x55d09af12284 - cargo::core::registry::PackageRegistry::ensure_loaded::hc907cec69fdeb5d3
                               at /checkout/cargo/src/cargo/core/registry.rs:191
                               at /checkout/cargo/src/cargo/util/errors.rs:58
                               at /checkout/cargo/src/cargo/core/registry.rs:180
                               at /checkout/cargo/src/cargo/core/registry.rs:141
  16:     0x55d09af1550b - <cargo::core::registry::PackageRegistry<'cfg> as cargo::core::registry::Registry>::query::hadbdbf4d0ac9bf3b
                               at /checkout/cargo/src/cargo/core/registry.rs:339

[matklad]

Looks like a duplicate of #3844?

[saleemrashid]

Fixed by rust-lang/rust#40625

[mgattozzi]

It might have been a duplicate @matklad. Either way the fix that @saleemrashid mentioned fixes my issue so I'm going to close this.