Fix icu_capi detection (#633)

* Fix `icu_capi` detection

#623 made `icu_capi` optional, which broke the build of servo
with vendored dependencies.
We need to explicitly add the `intl` feature when invoking cargo metadata, otherwise the feature will not be enabled
in the vendored crate directory when cargo metadata is run.

Signed-off-by: Jonathan Schwender <[email protected]>

* Update comment

Signed-off-by: Jonathan Schwender <[email protected]>

* Bump mozjs-sys version

Signed-off-by: Jonathan Schwender <[email protected]>

---------

Signed-off-by: Jonathan Schwender <[email protected]>

Author: jschwe

mozjs-sys/Cargo.toml

@@ -2,7 +2,7 @@
 name = "mozjs_sys"
 description = "System crate for the Mozilla SpiderMonkey JavaScript engine."
 repository.workspace = true
-version = "0.140.0-6"
+version = "0.140.0-7"
 authors = ["Mozilla", "The Servo Project Developers"]
 links = "mozjs"
 license.workspace = true

mozjs-sys/build.rs

@@ -4,6 +4,7 @@
 
 use bindgen::callbacks::ParseCallbacks;
 use bindgen::{CodegenConfig, Formatter, RustTarget};
+use cargo_metadata::CargoOpt;
 use std::ffi::{OsStr, OsString};
 use std::fmt::Write;
 use std::path::{Path, PathBuf};
@@ -138,9 +139,14 @@ fn main() {
 
 fn get_icu_capi_include_path() -> String {
     // Using cargo metadata is the official recommendation from the icu4x documentation.
-    // See <https://icu4x.unicode.org/2_0/cppdoc/>. In the future we should try to upstream a
-    // patch that allows us to use DEP_ syntax, like we do with libz.
-    let metadata = cargo_metadata::MetadataCommand::new().exec().unwrap();
+    // See <https://icu4x.unicode.org/2_0/cppdoc/>.
+    // Once we update to a new release containing https://github.com/unicode-org/icu4x/pull/6887
+    // we can remove the dependency on cargo metadata.
+    let metadata = cargo_metadata::MetadataCommand::new()
+        // icu_capi is feature guarded behind the `intl` feature.
+        .features(CargoOpt::SomeFeatures(vec!["intl".into()]))
+        .exec()
+        .unwrap();
     let packages = metadata.packages;
     let icu_capi_info = packages
         .iter()