commands, hugolib: Get file context in "config parse failed" errors

Fixes gohugoio#5325

commands/hugo.go

@@ -662,9 +662,10 @@ func (c *commandeer) fullRebuild() {
 	c.commandeerHugoState = &commandeerHugoState{}
 	err := c.loadConfig(true, true)
 	if err != nil {
-		c.logger.ERROR.Println("Failed to reload config:", err)
 		// Set the processing on pause until the state is recovered.
 		c.paused = true
+		c.handleBuildErr(err, "Failed to reload config")
+
 	} else {
 		c.paused = false
 	}

hugolib/config.go

@@ -16,10 +16,11 @@ package hugolib
 import (
 	"errors"
 	"fmt"
-
 	"io"
 	"strings"
 
+	"github.com/gohugoio/hugo/common/herrors"
+
 	"github.com/gohugoio/hugo/hugolib/paths"
 	_errors "github.com/pkg/errors"
 
@@ -106,12 +107,23 @@ func LoadConfig(d ConfigSourceDescriptor, doWithConfig ...func(cfg config.Provid
 	v.SetConfigFile(configFilenames[0])
 	v.AddConfigPath(d.Path)
 
+	applyFileContext := func(filename string, err error) error {
+		err, _ = herrors.WithFileContextForFile(
+			err,
+			filename,
+			filename,
+			fs,
+			herrors.SimpleLineMatcher)
+
+		return err
+	}
+
 	var configFileErr error
 
 	err := v.ReadInConfig()
 	if err != nil {
 		if _, ok := err.(viper.ConfigParseError); ok {
-			return nil, configFiles, err
+			return nil, configFiles, applyFileContext(v.ConfigFileUsed(), err)
 		}
 		configFileErr = ErrNoConfigFile
 	}
@@ -129,7 +141,7 @@ func LoadConfig(d ConfigSourceDescriptor, doWithConfig ...func(cfg config.Provid
 				return nil, configFiles, fmt.Errorf("Unable to open Config file.\n (%s)\n", err)
 			}
 			if err = v.MergeConfig(r); err != nil {
-				return nil, configFiles, fmt.Errorf("Unable to parse/merge Config file (%s).\n (%s)\n", configFile, err)
+				return nil, configFiles, applyFileContext(configFile, err)
 			}
 			configFiles = append(configFiles, configFile)
 		}

hugolib/hugo_sites_build_errors_test.go

@@ -30,7 +30,7 @@ func (t testSiteBuildErrorAsserter) assertLineNumber(lineNumber int, err error)
 func (t testSiteBuildErrorAsserter) assertErrorMessage(e1, e2 string) {
 	// The error message will contain filenames with OS slashes. Normalize before compare.
 	e1, e2 = filepath.ToSlash(e1), filepath.ToSlash(e2)
-	t.assert.Equal(e1, e2, trace())
+	t.assert.Contains(e2, e1, trace())
 
 }
 
@@ -102,8 +102,8 @@ func TestSiteBuildErrors(t *testing.T) {
 				fe := a.getFileError(err)
 				assert.Equal(5, fe.LineNumber)
 				assert.Equal(14, fe.ColumnNumber)
-				assert.Equal("md", fe.ChromaLexer)
-				a.assertErrorMessage("asdfadf", fe.Error())
+				assert.Equal("go-html-template", fe.ChromaLexer)
+				a.assertErrorMessage("\"layouts/_default/single.html:5:14\": execute of template failed", fe.Error())
 
 			},
 		},
@@ -124,7 +124,12 @@ func TestSiteBuildErrors(t *testing.T) {
 				return strings.Replace(content, ".Title", ".Titles", 1)
 			},
 			assertBuildError: func(a testSiteBuildErrorAsserter, err error) {
-				a.assertLineNumber(4, err)
+				fe := a.getFileError(err)
+				assert.Equal(7, fe.LineNumber)
+				assert.Equal("md", fe.ChromaLexer)
+				// Make sure that it contains both the content file and template
+				a.assertErrorMessage(`content/myyaml.md:7:10": failed to render shortcode "sc"`, fe.Error())
+				a.assertErrorMessage(`shortcodes/sc.html:4:22: executing "shortcodes/sc.html" at <.Page.Titles>: can't evaluate`, fe.Error())
 			},
 		},
 		{
@@ -173,7 +178,7 @@ func TestSiteBuildErrors(t *testing.T) {
 			},
 			assertBuildError: func(a testSiteBuildErrorAsserter, err error) {
 				assert.Error(err)
-				assert.Contains(err.Error(), "single.html")
+				assert.Contains(err.Error(), `"content/mytoml.md": render of "page" failed: execute of template failed: panic in Execute`)
 			},
 		},
 	}