updated errors.New usages

lib/main.go

@@ -120,6 +120,8 @@ var ErrBuildEPKTargetRootError = errors.New("error creating target root")
 var ErrBuildEPKExecutingBuildShError = errors.New("error executing build.sh")
 var ErrBuildEPKCountingFilesError = errors.New("error counting files")
 var ErrBuildEPKBadBuildType = errors.New("bad build type")
+var ErrBuildEPKDirectoryDoesNotExist = errors.New("required directory does not exist")
+var ErrBubbleWrapInsufficientPermissions = errors.New("bwrap does not have the necessary permissions")
 
 // BuildEPK builds the EPK package into a build directory
 func BuildEPK(projectDir string, inMemory bool, buildConfig Build, logger *Logger) (int64, string, error, error) {
@@ -226,7 +228,7 @@ func BuildEPK(projectDir string, inMemory bool, buildConfig Build, logger *Logge
 					Content: "Directory does not exist: " + dir,
 					Prompt:  false,
 				})
-				return 0, tempDir, err, errors.New("required directory does not exist: " + dir)
+				return 0, tempDir, err, ErrBuildEPKDirectoryDoesNotExist
 			}
 		}
 
@@ -254,7 +256,7 @@ func BuildEPK(projectDir string, inMemory bool, buildConfig Build, logger *Logge
 				Content: "bwrap is not available or does not have the necessary permissions",
 				Prompt:  false,
 			})
-			return 0, tempDir, err, errors.New("bwrap is not available or does not have the necessary permissions")
+			return 0, tempDir, err, ErrBubbleWrapInsufficientPermissions
 		}
 
 		arguments := []string{