Display which provider caused which error in output (#2757)

* Display which provider caused which error in output

Otherwise, the output is very difficult to parse.

Signed-off-by: Will Murphy <will.murphy@anchore.com>

* lint fix

Signed-off-by: Will Murphy <will.murphy@anchore.com>

* bump stereoscope to v0.0.2

Signed-off-by: Will Murphy <will.murphy@anchore.com>

---------

Signed-off-by: Will Murphy <will.murphy@anchore.com>

syft/get_source.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/anchore/syft/syft/source"
 )
@@ -21,21 +22,16 @@ func GetSource(ctx context.Context, userInput string, cfg *GetSourceConfig) (sou
 	}
 
 	var errs []error
-	var fileNotfound error
+	var fileNotFoundProviders []string
 
 	// call each source provider until we find a valid source
 	for _, p := range providers {
 		src, err := p.Provide(ctx)
 		if err != nil {
-			err = eachError(err, func(err error) error {
-				if errors.Is(err, os.ErrNotExist) {
-					fileNotfound = err
-					return nil
-				}
-				return err
-			})
-			if err != nil {
-				errs = append(errs, err)
+			if errors.Is(err, os.ErrNotExist) {
+				fileNotFoundProviders = append(fileNotFoundProviders, p.Name())
+			} else {
+				errs = append(errs, fmt.Errorf("%s: %w", p.Name(), err))
 			}
 		}
 		if src != nil {
@@ -52,8 +48,8 @@ func GetSource(ctx context.Context, userInput string, cfg *GetSourceConfig) (sou
 		}
 	}
 
-	if fileNotfound != nil {
-		errs = append([]error{fileNotfound}, errs...)
+	if len(fileNotFoundProviders) > 0 {
+		errs = append(errs, fmt.Errorf("additionally, the following providers failed with %w: %s", os.ErrNotExist, strings.Join(fileNotFoundProviders, ", ")))
 	}
 	return nil, sourceError(userInput, errs...)
 }
@@ -71,31 +67,3 @@ func sourceError(userInput string, errs ...error) error {
 	}
 	return fmt.Errorf("errors occurred attempting to resolve '%s':%s", userInput, errorTexts)
 }
-
-func eachError(err error, fn func(error) error) error {
-	out := fn(err)
-	// unwrap singly wrapped errors
-	if e, ok := err.(interface {
-		Unwrap() error
-	}); ok {
-		wrapped := e.Unwrap()
-		got := eachError(wrapped, fn)
-		// return the outer error if received the same wrapped error
-		if errors.Is(got, wrapped) {
-			return err
-		}
-		return got
-	}
-	// unwrap errors from errors.Join
-	if errs, ok := err.(interface {
-		Unwrap() []error
-	}); ok {
-		for _, e := range errs.Unwrap() {
-			e = eachError(e, fn)
-			if e != nil {
-				out = errors.Join(out, e)
-			}
-		}
-	}
-	return out
-}