Improve error messages, esp. when the server is running

* Add file context to minifier errors when publishing
* Misc fixes (see issues)
* Allow custom server error template in layouts/server/error.html

To get to this, this commit also cleans up and simplifies the code surrounding errors and files. This also removes the usage of `github.com/pkg/errors`, mostly because of https://github.com/pkg/errors/issues/223 -- but also because most of this is now built-in to Go.

Fixes #9852
Fixes #9857
Fixes #9863

2 files changed, 3 insertions, 14 deletions

diff --git a/resources/resource_transformers/tocss/dartsass/transform.go b/resources/resource_transformers/tocss/dartsass/transform.go
index 79c32fcfd..082e30710 100644
--- a/resources/resource_transformers/tocss/dartsass/transform.go
+++ b/resources/resource_transformers/tocss/dartsass/transform.go
@@ -120,18 +120,8 @@ func (t *transform) Transform(ctx *resources.ResourceTransformationCtx) error {
 				return m.Offset+len(m.Line) >= start.Offset && strings.Contains(m.Line, context)
 			}
 
-			ferr, ok := herrors.WithFileContextForFile(
-				herrors.NewFileError("scss", -1, -1, start.Column, sassErr),
-				filename,
-				filename,
-				hugofs.Os,
-				offsetMatcher)
-
-			if !ok {
-				return sassErr
-			}
+			return herrors.NewFileErrorFromFile(sassErr, filename, filename, hugofs.Os, offsetMatcher)
 
-			return ferr
 		}
 		return err
 	}
diff --git a/resources/resource_transformers/tocss/scss/tocss.go b/resources/resource_transformers/tocss/scss/tocss.go
index 802798e59..f9f4786f5 100644
--- a/resources/resource_transformers/tocss/scss/tocss.go
+++ b/resources/resource_transformers/tocss/scss/tocss.go
@@ -28,7 +28,6 @@ import (
 	"github.com/gohugoio/hugo/hugofs"
 	"github.com/gohugoio/hugo/media"
 	"github.com/gohugoio/hugo/resources"
-	"github.com/pkg/errors"
 )
 
 // Used in tests. This feature requires Hugo to be built with the extended tag.
@@ -172,7 +171,7 @@ func (c *Client) toCSS(options libsass.Options, dst io.Writer, src io.Reader) (l
 	in := helpers.ReaderToString(src)
 
 	// See https://github.com/gohugoio/hugo/issues/7059
-	// We need to preserver the regular CSS imports. This is by far
+	// We need to preserve the regular CSS imports. This is by far
 	// a perfect solution, and only works for the main entry file, but
 	// that should cover many use cases, e.g. using SCSS as a preprocessor
 	// for Tailwind.
@@ -181,7 +180,7 @@ func (c *Client) toCSS(options libsass.Options, dst io.Writer, src io.Reader) (l
 
 	res, err = transpiler.Execute(in)
 	if err != nil {
-		return res, errors.Wrap(err, "SCSS processing failed")
+		return res, fmt.Errorf("SCSS processing failed: %w", err)
 	}
 
 	out := res.CSS