`./mach check` errors while `./mach build --dev` builds.

[gatoWololo]

I currently have a successfully building Servo with ./mach build --dev:

gatowololo@omar-mozilla ~/S/servo> ./mach build --dev
   Compiling script v0.0.1 (/home/gatowololo/Servo/servo/components/script)
   Compiling layout_thread v0.0.1 (/home/gatowololo/Servo/servo/components/layout_thread)
   Compiling libservo v0.0.1 (/home/gatowololo/Servo/servo/components/servo)
   Compiling servo v0.0.1 (/home/gatowololo/Servo/servo/ports/glutin)

... Warning messages...

    Finished dev [unoptimized + debuginfo] target(s) in 1m 26s
Build Completed in 0:01:26

But ./mach check fails:

gatowololo@omar-mozilla ~/S/servo> ./mach check
   Compiling script v0.0.1 (/home/gatowololo/Servo/servo/components/script)
    Checking canvas v0.0.1 (/home/gatowololo/Servo/servo/components/canvas)
error[E0425]: cannot find function `create_backend` in this scope
   --> components/canvas/canvas_data.rs:411:23
    |
411 |         let backend = create_backend();
    |                       ^^^^^^^^^^^^^^ not found in this scope

error[E0392]: parameter `'a` is never used
   --> components/canvas/canvas_data.rs:379:23
    |
379 | pub struct CanvasData<'a> {
    |                       ^^ unused parameter
    |
    = help: consider removing `'a` or using a marker such as `std::marker::PhantomData`

error[E0392]: parameter `'a` is never used
  --> components/canvas/canvas_paint_thread.rs:18:30
   |
18 | pub struct CanvasPaintThread<'a> {
   |                              ^^ unused parameter
   |
   = help: consider removing `'a` or using a marker such as `std::marker::PhantomData`

error[E0392]: parameter `'a` is never used
   --> components/canvas/canvas_data.rs:366:24
    |
366 | pub enum StrokeOptions<'a> {
    |                        ^^ unused parameter
    |
    = help: consider removing `'a` or using a marker such as `std::marker::PhantomData`

error[E0392]: parameter `'a` is never used
    --> components/canvas/canvas_data.rs:1099:29
     |
1099 | pub struct CanvasPaintState<'a> {
     |                             ^^ unused parameter
     |
     = help: consider removing `'a` or using a marker such as `std::marker::PhantomData`

error: aborting due to 5 previous errors

Some errors have detailed explanations: E0392, E0425.
For more information about an error, try `rustc --explain E0392`.
error: Could not compile `canvas`.
warning: build failed, waiting for other jobs to finish...
error: build failed

Not sure if I'm doing something wrong?

I'm running:

Ubuntu 19.04
Kernel: 5.0.0-15-generic
cargo 1.36.0-nightly (759b6161a 2019-05-06)

[jdm]

Bleah, that's a regression from #23451. You can work around with with ./mach check --features azure_backend.

[KiChjang]

How does one fix this? Is it a matter of invoking cargo via the python scripts with the right feature flags?

[jdm]

The answer is to hard code the features flag in the python that invokes cargo check.