Pin CI to Rust nightly-2025-06-23. (#1486)

This works around the issue filed upstream in rust-lang/rust#143164.

Author: sunfishcode

.github/workflows/main.yml

@@ -25,14 +25,14 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        build: [stable, nightly, 1.63]
+        build: [stable, nightly-2025-06-23, 1.63]
         include:
           - build: stable
             os: ubuntu-latest
             rust: stable
-          - build: nightly
+          - build: nightly-2025-06-23
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
           - build: 1.63
             os: ubuntu-latest
             rust: 1.63
@@ -144,11 +144,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        build: [nightly]
+        build: [nightly-2025-06-23]
         include:
-          - build: nightly
+          - build: nightly-2025-06-23
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
 
     env:
       # -D warnings is commented out in our install-rust action; re-add it here.
@@ -176,11 +176,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        build: [nightly]
+        build: [nightly-2025-06-23]
         include:
-          - build: nightly
+          - build: nightly-2025-06-23
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
 
     steps:
     - uses: actions/checkout@v4
@@ -201,11 +201,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        build: [nightly]
+        build: [nightly-2025-06-23]
         include:
-          - build: nightly
+          - build: nightly-2025-06-23
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
 
     steps:
     - uses: actions/checkout@v4
@@ -254,20 +254,20 @@ jobs:
         include:
           - build: ubuntu
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
           - build: ubuntu-22.04
             os: ubuntu-22.04
-            rust: nightly
+            rust: nightly-2025-06-23
           - build: i686-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: i686-unknown-linux-gnu
             gcc_package: gcc-i686-linux-gnu
             gcc: i686-linux-gnu-gcc
             libc_package: libc-dev-i386-cross
           - build: aarch64-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: aarch64-unknown-linux-gnu
             gcc_package: gcc-aarch64-linux-gnu
             gcc: aarch64-linux-gnu-gcc
@@ -276,7 +276,7 @@ jobs:
             qemu_target: aarch64-linux-user
           - build: powerpc-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: powerpc-unknown-linux-gnu
             gcc_package: gcc-powerpc-linux-gnu
             gcc: powerpc-linux-gnu-gcc
@@ -285,7 +285,7 @@ jobs:
             qemu_target: ppc-linux-user
           - build: powerpc64le-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: powerpc64le-unknown-linux-gnu
             gcc_package: gcc-powerpc64le-linux-gnu
             gcc: powerpc64le-linux-gnu-gcc
@@ -294,7 +294,7 @@ jobs:
             qemu_target: ppc64le-linux-user
           - build: riscv64-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: riscv64gc-unknown-linux-gnu
             gcc_package: gcc-riscv64-linux-gnu
             gcc: riscv64-linux-gnu-gcc
@@ -303,7 +303,7 @@ jobs:
             qemu_target: riscv64-linux-user
           - build: s390x-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: s390x-unknown-linux-gnu
             gcc_package: gcc-s390x-linux-gnu
             gcc: s390x-linux-gnu-gcc
@@ -312,7 +312,7 @@ jobs:
             qemu_target: s390x-linux-user
           - build: arm-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: armv5te-unknown-linux-gnueabi
             gcc_package: gcc-arm-linux-gnueabi
             gcc: arm-linux-gnueabi-gcc
@@ -455,10 +455,10 @@ jobs:
             rust: stable
           - build: windows
             os: windows-latest
-            rust: nightly
+            rust: nightly-2025-06-23
           - build: windows-2019
             os: windows-2019
-            rust: nightly
+            rust: nightly-2025-06-23
           - build: musl
             os: ubuntu-latest
             rust: stable
@@ -708,7 +708,7 @@ jobs:
         include:
           - build: powerpc-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: powerpc-unknown-linux-gnu
             gcc_package: gcc-powerpc-linux-gnu
             gcc: powerpc-linux-gnu-gcc
@@ -717,7 +717,7 @@ jobs:
             qemu_target: ppc-linux-user
           - build: powerpc64le-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: powerpc64le-unknown-linux-gnu
             gcc_package: gcc-powerpc64le-linux-gnu
             gcc: powerpc64le-linux-gnu-gcc
@@ -726,7 +726,7 @@ jobs:
             qemu_target: ppc64le-linux-user
           - build: s390x-linux
             os: ubuntu-latest
-            rust: nightly
+            rust: nightly-2025-06-23
             target: s390x-unknown-linux-gnu
             gcc_package: gcc-s390x-linux-gnu
             gcc: s390x-linux-gnu-gcc