rust toolchain: use RUSTC_BOOTSTRAP when building

Reviewed By: mitrandir77

Differential Revision: D18850917

fbshipit-source-id: f211dfbfadf4b5b0cb372cf8aeb9a232c4b3a739

build/fbcode_builder/getdeps/builder.py

@@ -822,6 +822,8 @@ class CargoBuilder(BuilderBase):
     def run_cargo(self, install_dirs, operation, args=None):
         args = args or []
         env = self._compute_env(install_dirs)
+        # Enable using nightly features with stable compiler
+        env["RUSTC_BOOTSTRAP"] = "1"
         cmd = ["cargo", operation, "-j%s" % self.build_opts.num_jobs] + args
         self._run_cmd(cmd, cwd=self.build_source_dir(), env=env)
 

build/fbcode_builder/manifests/eden

@@ -22,7 +22,7 @@ lz4
 python-toml
 
 [dependencies.fb=on]
-rust-stable
+rust
 
 # macOS ships with sqlite3, and some of the core system
 # frameworks require that that version be linked rather

build/fbcode_builder/manifests/rust-shed

@@ -26,4 +26,4 @@ tools/rust/ossconfigs = .
 fbthrift
 
 [dependencies.fb=on]
-rust-nightly
+rust