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

1 files changed, 9 insertions, 9 deletions

diff --git a/modules/collect.go b/modules/collect.go
index e012d4696..ff83f9ecc 100644
--- a/modules/collect.go
+++ b/modules/collect.go
@@ -36,7 +36,7 @@ import (
 
 	"github.com/rogpeppe/go-internal/module"
 
-	"github.com/pkg/errors"
+	"errors"
 
 	"github.com/gohugoio/hugo/config"
 	"github.com/spf13/afero"
@@ -48,7 +48,7 @@ const vendorModulesFilename = "modules.txt"
 
 // IsNotExist returns whether an error means that a module could not be found.
 func IsNotExist(err error) bool {
-	return errors.Cause(err) == ErrNotExist
+	return errors.Is(err, os.ErrNotExist)
 }
 
 // CreateProjectModule creates modules from the given config.
@@ -289,7 +289,7 @@ func (c *collector) add(owner *moduleAdapter, moduleImport Import, disabled bool
 					return nil, nil
 				}
 				if found, _ := afero.Exists(c.fs, moduleDir); !found {
-					c.err = c.wrapModuleNotFound(errors.Errorf(`module %q not found; either add it as a Hugo Module or store it in %q.`, modulePath, c.ccfg.ThemesDir))
+					c.err = c.wrapModuleNotFound(fmt.Errorf(`module %q not found; either add it as a Hugo Module or store it in %q.`, modulePath, c.ccfg.ThemesDir))
 					return nil, nil
 				}
 			}
@@ -297,7 +297,7 @@ func (c *collector) add(owner *moduleAdapter, moduleImport Import, disabled bool
 	}
 
 	if found, _ := afero.Exists(c.fs, moduleDir); !found {
-		c.err = c.wrapModuleNotFound(errors.Errorf("%q not found", moduleDir))
+		c.err = c.wrapModuleNotFound(fmt.Errorf("%q not found", moduleDir))
 		return nil, nil
 	}
 
@@ -557,7 +557,7 @@ func (c *collector) collectModulesTXT(owner Module) error {
 		line = strings.TrimSpace(line)
 		parts := strings.Fields(line)
 		if len(parts) != 2 {
-			return errors.Errorf("invalid modules list: %q", filename)
+			return fmt.Errorf("invalid modules list: %q", filename)
 		}
 		path := parts[0]
 
@@ -662,7 +662,7 @@ func (c *collector) normalizeMounts(owner *moduleAdapter, mounts []Mount) ([]Mou
 			targetBase = mnt.Target[0:idxPathSep]
 		}
 		if !files.IsComponentFolder(targetBase) {
-			return nil, errors.Errorf("%s: mount target must be one of: %v", errMsg, files.ComponentFolders)
+			return nil, fmt.Errorf("%s: mount target must be one of: %v", errMsg, files.ComponentFolders)
 		}
 
 		out = append(out, mnt)
@@ -672,7 +672,7 @@ func (c *collector) normalizeMounts(owner *moduleAdapter, mounts []Mount) ([]Mou
 }
 
 func (c *collector) wrapModuleNotFound(err error) error {
-	err = errors.Wrap(ErrNotExist, err.Error())
+	err = fmt.Errorf(err.Error()+": %w", ErrNotExist)
 	if c.GoModulesFilename == "" {
 		return err
 	}
@@ -681,9 +681,9 @@ func (c *collector) wrapModuleNotFound(err error) error {
 
 	switch c.goBinaryStatus {
 	case goBinaryStatusNotFound:
-		return errors.Wrap(err, baseMsg+" you need to install Go to use it. See https://golang.org/dl/.")
+		return fmt.Errorf(baseMsg+" you need to install Go to use it. See https://golang.org/dl/ : %q", err)
 	case goBinaryStatusTooOld:
-		return errors.Wrap(err, baseMsg+" you need to a newer version of Go to use it. See https://golang.org/dl/.")
+		return fmt.Errorf(baseMsg+" you need to a newer version of Go to use it. See https://golang.org/dl/ : %w", err)
 	}
 
 	return err