Update to Go 1.15

Fixes gohugoio#7554

.circleci/config.yml

@@ -1,6 +1,6 @@
 defaults: &defaults
   docker:
-      - image: bepsays/ci-goreleaser:1.14.3
+      - image: bepsays/ci-goreleaser:1.15.0
   environment:
     CGO_ENABLED: "0"
 

.travis.yml

@@ -12,8 +12,8 @@ env:
 git:
   depth: false
 go:
-  - "1.13.11"
-  - "1.14.3"
+  - "1.14.7"
+  - "1.15"
   - master
 
 arch:

magefile.go

@@ -44,17 +44,17 @@ func init() {
 
 // Build hugo binary
 func Hugo() error {
-	return sh.RunWith(flagEnv(), goexe, "build", "-ldflags", ldflags, "-tags", buildTags(), packageName)
+	return sh.RunWith(flagEnv(), goexe, "build", "-ldflags", ldflags, buildFlags(), "-tags", buildTags(), packageName)
 }
 
 // Build hugo binary with race detector enabled
 func HugoRace() error {
-	return sh.RunWith(flagEnv(), goexe, "build", "-race", "-ldflags", ldflags, "-tags", buildTags(), packageName)
+	return sh.RunWith(flagEnv(), goexe, "build", "-race", "-ldflags", ldflags, buildFlags(), "-tags", buildTags(), packageName)
 }
 
 // Install hugo binary
 func Install() error {
-	return sh.RunWith(flagEnv(), goexe, "install", "-ldflags", ldflags, "-tags", buildTags(), packageName)
+	return sh.RunWith(flagEnv(), goexe, "install", "-ldflags", ldflags, buildFlags(), "-tags", buildTags(), packageName)
 }
 
 // Uninstall hugo binary
@@ -176,13 +176,13 @@ func Test386() error {
 // Run tests
 func Test() error {
 	env := map[string]string{"GOFLAGS": testGoFlags()}
-	return runCmd(env, goexe, "test", "./...", "-tags", buildTags())
+	return runCmd(env, goexe, "test", "./...", buildFlags(), "-tags", buildTags())
 }
 
 // Run tests with race detector
 func TestRace() error {
 	env := map[string]string{"GOFLAGS": testGoFlags()}
-	return runCmd(env, goexe, "test", "-race", "./...", "-tags", buildTags())
+	return runCmd(env, goexe, "test", "-race", "./...", buildFlags(), "-tags", buildTags())
 }
 
 // Run gofmt linter
@@ -338,6 +338,13 @@ func isCI() bool {
 	return os.Getenv("CI") != ""
 }
 
+func buildFlags() string {
+	if runtime.GOOS == "windows" {
+		return "-buildmode exe"
+	}
+	return ""
+}
+
 func buildTags() string {
 	// To build the extended Hugo SCSS/SASS enabled version, build with
 	// HUGO_BUILD_TAGS=extended mage install etc.

snap/snapcraft.yaml

@@ -26,7 +26,7 @@ parts:
 
   hugo:
     plugin: nil
-    build-snaps: [go/1.14/stable]
+    build-snaps: [go/1.15/stable]
     source: .
     override-build: |
       set -ex