test failures with Rust 1.57

[apteryks]

Hello, attempting to build concolor-control@0.0.7 on Guix, I get the following test failure:

starting phase `check'
   Compiling concolor-control v0.0.7 (/tmp/guix-build-rust-concolor-control-0.0.7.drv-0/concolor-control-0.0.7)
    Finished test [unoptimized + debuginfo] target(s) in 0.21s
     Running unittests (target/debug/deps/concolor_control-862b70130982a923)

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

   Doc-tests concolor-control

running 2 tests
test src/lib.rs - (line 31) ... FAILED
test src/lib.rs - (line 62) ... ok

failures:

---- src/lib.rs - (line 31) stdout ----
error[E0425]: cannot find function `set` in crate `concolor_control`
  --> src/lib.rs:33:19
   |
5  | concolor_control::set(when);
   |                   ^^^ help: a function with a similar name exists: `get`
   |
  ::: /tmp/guix-build-rust-concolor-control-0.0.7.drv-0/concolor-control-0.0.7/src/no_color.rs:21:1
   |
21 | pub fn get(_stream: crate::Stream) -> Color {
   | ------------------------------------------- similarly named function `get` defined here

error: aborting due to previous error

For more information about this error, try `rustc --explain E0425`.
Couldn't compile the test.

failures:
    src/lib.rs - (line 31)

test result: FAILED. 1 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.15s

error: test failed, to rerun pass '--doc'
error: in phase 'check': uncaught exception:
%exception #<&invoke-error program: "cargo" arguments: ("test") exit-status: 101 term-signal: #f stop-signal: #f> 
phase `check' failed after 0.4 seconds

It is probably related the doctest problem (?) in Rust 1.57 that also causes xiph/rav1e#2851.

[epage]

The problem is that test requires api_unstable feature. When we test in the workspace, features get unified and so it becomes enabled. When testing just the crate, there is no feature unification and the doc test fails.

[epage]

api_unstable is now gone.