compose: try all possible providers before throwing an error

Do not error out immediately but collect all errors and report them if
no candidate succeeded.  That'll fix containers#20502 and improve the quality of
reported errors.

[NO NEW TESTS NEEDED]

Fixes: containers#20502
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

cmd/podman/compose.go

@@ -17,6 +17,7 @@ import (
 
 	"github.com/containers/common/pkg/config"
 	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/containers/podman/v4/pkg/errorhandling"
 	"github.com/containers/podman/v4/pkg/machine"
 	"github.com/containers/podman/v4/pkg/machine/provider"
 	"github.com/sirupsen/logrus"
@@ -85,20 +86,19 @@ func composeProvider() (string, error) {
 		return "", errors.New("no compose provider specified, please refer to `man podman-compose` for details")
 	}
 
+	lookupErrors := make([]error, 0, len(candidates))
 	for _, candidate := range candidates {
 		path, err := exec.LookPath(os.ExpandEnv(candidate))
-		if err != nil {
-			if errors.Is(err, os.ErrNotExist) {
-				continue
-			}
-			return "", err
+		if err == nil {
+			// First specified provider "candidate" wins.
+			logrus.Debugf("Found compose provider %q", path)
+			return path, nil
 		}
-		// First specified provider "candidate" wins.
-		logrus.Debugf("Found compose provider %q", path)
-		return path, nil
+		logrus.Debugf("Error looking up compose provider %q: %v", path, err)
+		lookupErrors = append(lookupErrors, err)
 	}
 
-	return "", errors.New("no configured compose provider found on system, please refer to the documentation for details")
+	return "", fmt.Errorf("looking up compose provider failed\n%v", errorhandling.JoinErrors(lookupErrors))
 }
 
 // composeDockerHost returns the value to be set in the DOCKER_HOST environment