Use stable version to compute code coverage

Author: Luni-4

.taskcluster.yml

@@ -96,18 +96,20 @@ tasks:
         workerType: ci
         payload:
           maxRunTime: 3600
-          image: "rustlang/rust:nightly"
+          image: "rust:buster"
           env:
             CODECOV_TOKEN: 4df01912-087e-489a-be28-25aa911cb9d2
             CARGO_INCREMENTAL: 0
-            RUSTFLAGS: -Zprofile -Ccodegen-units=1 -Copt-level=0 -Clink-dead-code -Coverflow-checks=off -Zpanic_abort_tests -Cpanic=abort
+            RUSTFLAGS: -Cinstrument-coverage
             RUSTDOCFLAGS: -Cpanic=abort
+            LLVM_PROFILE_FILE: rust-code-analysis-%p-%m.profraw
           command:
             - "/bin/bash"
             - "-cx"
             - "apt-get -qq update &&
                apt-get -qq install -y zip &&
                curl -L https://github.com/mozilla/grcov/releases/download/v0.8.6/grcov-v0.8.6-x86_64-unknown-linux-gnu.tar.gz | tar xz &&
+               rustup component add llvm-tools-preview &&
                git clone --quiet ${repository} &&
                cd rust-code-analysis &&
                git -c advice.detachedHead=false checkout ${head_rev} &&