Use minimal dependency versions for MSRV tests on CI (#1109)

.github/workflows/CI.yml

@@ -2,6 +2,7 @@ name: CI
 
 env:
   CARGO_TERM_COLOR: always
+  MSRV: 1.56.0
 
 on:
   push:
@@ -88,8 +89,8 @@ jobs:
         command: test
         args: --all --all-features --all-targets
 
-  # some examples doesn't support 1.56 (such as async-graphql)
+  # some examples doesn't support our MSRV (such as async-graphql)
-  # so we only test axum itself on 1.56
+  # so we only test axum itself on our MSRV
   test-msrv:
     needs: check
     runs-on: ubuntu-latest
@@ -97,10 +98,21 @@ jobs:
     - uses: actions/checkout@master
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: 1.56
+        toolchain: ${{ env.MSRV }}
         override: true
         profile: minimal
+    - name: "install Rust nightly"
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: nightly
+        profile: minimal
     - uses: Swatinem/rust-cache@v1
+    - name: Select minimal versions
+      uses: actions-rs/cargo@v1
+      with:
+        command: update
+        args: -Z minimal-versions
+        toolchain: nightly
     - name: Run tests
       uses: actions-rs/cargo@v1
       with:
@@ -109,8 +121,12 @@ jobs:
           -p axum
           -p axum-extra
           -p axum-core
-          --all-features --all-targets
+          -p internal-minimal-versions
-    # the compiler errors are different on 1.56 which makes
+          --all-features
+          --all-targets
+          --locked
+        toolchain: ${{ env.MSRV }}
+    # the compiler errors are different on our MSRV which makes
     # the trybuild tests in axum-macros fail, so just run the doc
     # tests
     - name: Run axum-macros doc tests
@@ -119,8 +135,11 @@ jobs:
         command: test
         args: >
           -p axum-macros
+          -p internal-minimal-versions
           --doc
           --all-features
+          --locked
+        toolchain: ${{ env.MSRV }}
 
   test-docs:
     needs: check

Cargo.toml

@@ -4,4 +4,9 @@ members = [
     "axum-core",
     "axum-extra",
     "axum-macros",
+
+    # internal crate used to bump the minimum versions we
+    # get for some dependencies which otherwise wouldn't build
+    # with `cargo +nightly update -Z minimal-versions`
+    "internal-minimal-versions",
 ]

axum-macros/Cargo.toml

@@ -26,4 +26,4 @@ rustversion = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 syn = { version = "1.0", features = ["full", "extra-traits"] }
 tokio = { version = "1.0", features = ["full"] }
-trybuild = "1.0"
+trybuild = "1.0.63"

axum/Cargo.toml

@@ -48,7 +48,7 @@ tower-service = "0.3"
 
 # optional dependencies
 base64 = { version = "0.13", optional = true }
-headers = { version = "0.3", optional = true }
+headers = { version = "0.3.7", optional = true }
 multer = { version = "2.0.0", optional = true }
 serde_json = { version = "1.0", features = ["raw_value"], optional = true }
 serde_urlencoded = { version = "0.7", optional = true }
@@ -60,7 +60,7 @@ anyhow = "1.0"
 futures = "0.3"
 quickcheck = "1.0"
 quickcheck_macros = "1.0"
-reqwest = { version = "0.11", default-features = false, features = ["json", "stream", "multipart"] }
+reqwest = { version = "0.11.11", default-features = false, features = ["json", "stream", "multipart"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 tokio = { version = "1.6.1", features = ["macros", "rt", "rt-multi-thread", "net", "test-util"] }

internal-minimal-versions/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "internal-minimal-versions"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+# these dependencies don't build if installed with `cargo +nightly update -Z
+# minimal-versions` so we add them here to make sure we get a version that
+# does build
+#
+# this only matters for axum's CI
+[dependencies]
+crc32fast = "1.3.2"
+gcc = "0.3.55"
+time = "0.3.9"
+tungstenite = "0.17.2"

internal-minimal-versions/src/lib.rs

@@ -0,0 +1 @@
+// intentionally left empty