From 263092085d15a159d867d3fddfa3ca38e8fd9230 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= <berykubik@gmail.com>
Date: Wed, 16 Apr 2025 08:52:22 +0200
Subject: [PATCH] Pin rustc used for the `proc-macro-src` CI job

---
 .github/workflows/ci.yaml | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 84524201c3..79fb7a2d2e 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -46,17 +46,25 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.head.sha }}
 
+      - name: Install rustup-toolchain-install-master
+        run: cargo install rustup-toolchain-install-master@1.6.0
+
+      # Install a pinned rustc commit to avoid surprises
       - name: Install Rust toolchain
         run: |
-          rustup update --no-self-update nightly
-          rustup default nightly
-          rustup component add --toolchain nightly rust-src rustfmt
+          RUSTC_VERSION=`cat rust-version`
+          rustup-toolchain-install-master ${RUSTC_VERSION} -c rust-src -c rustfmt
+          rustup default ${RUSTC_VERSION}
+
+      # Emulate a nightly toolchain, because the toolchain installed above does not have "nightly"
+      # in its version string.
+      - name: Emulate a nightly toolchain
+        run: echo "RUSTC_BOOTSTRAP=1" >> $GITHUB_ENV
+
       # https://github.com/actions-rust-lang/setup-rust-toolchain/blob/main/rust.json
       - name: Install Rust Problem Matcher
         run: echo "::add-matcher::.github/rust.json"
 
-      # We don't cache this job, as it will be invalidated every day due to nightly usage
-
       - name: Test
         run: cargo test --features sysroot-abi -p proc-macro-srv -p proc-macro-srv-cli -p proc-macro-api -- --quiet