Servo build fails at linking

[pyfisch]

https://gist.github.com/pyfisch/b87045ec5b24d07eb87cd867d1dd6b95

I have installed the dependencies listed in the readme. I already did a clean rebuild.
Any suggestions what causes this failure?

Current revision is:

$ git rev-parse HEAD
92cbf5630966c2a3f655e1edefa451628f2811ef

I am using Ubuntu 16.04.

[emilio]

error: undefined reference to 'GeckoMedia_Initialize'
error: undefined reference to 'GeckoMedia_ProcessEvents'
error: undefined reference to 'GeckoMedia_Shutdown'
error: undefined reference to 'GeckoMedia_CanPlayType'

cc @nox @philn ^

[philn]

Can you check if gecko-media alone builds correctly? Try to run the unit-tests locally or the standalone player.

[pyfisch]

@philn: It does not even build on Travis CI.
The reported error is:

error: Package `serde_derive v1.0.23` does not have these features: `deserialize_from`

Some package seems to have changed under gecko-media. servo itself is protected from this because it distributes a lockfile along with the source code but I don't know how to extract the relevant portions for gecko-media.

[philn]

Ah, a workaround was suggested on IRC about this Serde issue. Put this in gecko-media's Cargo.toml:

[patch.crates-io]
serde = { git = "https://github.com/gankro/serde", branch = "deserialize_from_enums3" }
serde_derive = { git = "https://github.com/gankro/serde", branch = "deserialize_from_enums3", feature="deserialize_from" }

But I think this should be properly fixed somehow... CC @nox @Eijebong

[philn]

This happens because of the examples dependency on webrender.

[pyfisch]

Okay, executing cargo build -p gecko-media succeeds with the workaround.

Still building the examples fails with a version mismatch:

error: failed to select a version for `serde` (required by `webrender_api`):
all possible versions conflict with previously selected versions of `serde`
  version 1.0.24 in use by serde v1.0.24
  possible versions to select: 1.0.23

[Eijebong]

cc @gankro too since it's the custom serde fork that's causing all this.

[Gankra]

Traveling, if I don’t get back to this tomorrow please reping.

(Not sure: it looks like you’re trying to use a version of serde that’s newer than the patch?)

[Eijebong]

Well the [patch.crates-io] section from webrender seems to be ineffective in crates using webrender as a dependency. Not sure if this is the desired behavior but I think this is what causing those errors.

[Gankra]

Yes patch only applies to binary projects. You can’t apply it to a lib.

[staktrace]

Some things to try:

• Leave the [patch.crates-io] section in your gecko-media workspace's Cargo.toml, and make sure the version of webrender it's trying to build is f9bc4a5c or newer ; that might fix the problem
• If that doesn't work, try running cargo update -p serde --precise 1.0.23 which should change your Cargo.lock file to use serde 1.0.23 instead of 1.0.24, and the error with the conflicting versions should go away
• If neither of those work, try rolling back the version of webrender to e558d41b or earlier ; that will use a version of webrender prior to the serde patching - you will also need to remove the [patch.crates-io] from your gecko-media workspace's Cargo.toml.

(To pin webrender to a particular version you would edit the examples/Cargo.toml file and add a rev = ... attribute into the dependencies.webrender key)

[pyfisch]

#19806 removed gecko-media so this is no longer an issue.