[ci] Pin nightly docs workflow rust version to nightly-2022-01-25

diff --git a/.github/workflows/nightly_docs.yml b/.github/workflows/nightly_docs.yml
index 9ec7fe5c35bcd42b5576de0a56b3da91cfd19d2b..a82beb2de98449fe9274dae50cd43c680dbbbadb 100644 (file)
--- a/.github/workflows/nightly_docs.yml
+++ b/.github/workflows/nightly_docs.yml
@@ -18,7 +18,7 @@ jobs:
             target
           key: nightly-docs-${{ hashFiles('**/Cargo.toml','**/Cargo.lock') }}
       - name: Set default toolchain
-        run: rustup default nightly
+        run: rustup default nightly-2022-01-25
       - name: Set profile
         run: rustup set profile minimal
       - name: Update toolchain