github action: update for go1.17 and fix checks for PRs

- Use go1.17 for github actions.
- Use go mod edit instead of go get for testing other packages. There's two
  benefits:
  - This removes the round trip to pkg.go.dev and use the already present local
    checkout.
  - The go get periph.io/x/conn/v3@${GITHUB_SHA} command worked if a maintainer
    push a branch, but fails for a PR. This is because the go get command does a
    clone with all the branches, so it finds the commit even if it's not in main.
    For a PR, one has to pull a specific refs/pull/ID/head ref that is not a
    branch, thus go get cannot find it because git clone doesn't know about it.
    The only way to work around is to git clone manually.
- Remove 'go version' and 'go env' since they are already run as part of
  setup-go@v2.
- Fix a new check in go vet in example code.

.github/workflows/test.yml

@@ -24,7 +24,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
         # Do not forget to bump every 6 months!
-        gover: ["1.16"]
+        gover: ["1.17"]
     runs-on: "${{matrix.os}}"
     name: "go${{matrix.gover}}.x on ${{matrix.os}}"
     steps:
@@ -36,10 +36,6 @@ jobs:
     - name: Turn off git core.autocrlf
       run: git config --global core.autocrlf false
     - uses: actions/checkout@v2
-    - name: 'go version'
-      run: go version
-    - name: 'go env'
-      run: go env
     - name: "Debug"
       run: |
         echo HOME = $HOME
@@ -53,7 +49,7 @@ jobs:
       uses: actions/cache@v2
       with:
         path: ~/go
-        key: "${{runner.os}}-gopkg-${{hashFiles('go.sum', '.github/workflows/*.yml')}}-v2"
+        key: "${{runner.os}}-gopkg-${{hashFiles('go.sum', '.github/workflows/*.yml')}}"
 
       # Fetch the tools before checking out, so they don't modify go.mod/go.sum.
     - name: 'go get necessary tools'
@@ -148,9 +144,11 @@ jobs:
       run: rm coverage.txt
       # Don't run go test -race if anything failed, to speed up the results.
     - name: 'Check: go test -race'
-      run: go test -timeout=40s -race ./...
+      run: go test -timeout=60s -race ./...
     - name: 'Check: go test -bench .'
       run: go test -timeout=40s -bench . -benchtime=100ms -cpu=1 ./...
+    - name: 'Check: CGO_ENABLED=0 go test -short'
+      run: CGO_ENABLED=0 go test -timeout=40s -short ./...
 
     - name: "Check: tree is clean"
       run: |
@@ -195,7 +193,8 @@ jobs:
         cd ..
         git clone https://github.com/periph/cmd
         cd cmd
-        go get periph.io/x/devices/v3@${GITHUB_SHA}
+        go mod edit -replace=periph.io/x/devices/v3=../devices
+        go get ./...
         go test -short ./...
 
     - name: 'Send comments'

st7567/example_test.go

@@ -63,7 +63,7 @@ func Example() {
 	}()
 
 	//Control-C trap
-	c := make(chan os.Signal)
+	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
 	go func() {
 		<-c