Update error printing

src/error.rs

@@ -1,7 +1,7 @@
 use crate::launch::ProcfileConversionError;
 use crate::procfile::ProcfileParsingError;
+use bullet_stream::Print;
 use indoc::formatdoc;
-use libherokubuildpack::log::log_error;
 
 #[derive(Debug)]
 pub(crate) enum ProcfileBuildpackError {
@@ -11,37 +11,36 @@ pub(crate) enum ProcfileBuildpackError {
 }
 
 pub(crate) fn error_handler(buildpack_error: ProcfileBuildpackError) {
+    let build_output = Print::new(std::io::stdout()).without_header();
     match buildpack_error {
         ProcfileBuildpackError::CannotReadProcfileContents(io_error) => {
-            log_error(
-                "Cannot read Procfile contents",
-                formatdoc! {"
-                    Please ensure the Procfile in the root of your application is a readable UTF-8
-                    encoded file and try again.
-
-                    Underlying cause was: {io_error}
-                "},
-            );
+            build_output.error(formatdoc! {"
+                Cannot read Procfile contents
+
+                Please ensure the Procfile in the root of your application is a readable UTF-8
+                encoded file and try again.
+
+                Underlying cause was: {io_error}
+            "});
         }
         // There are currently no ways in which parsing can fail, however we will add some in the future:
         // https://github.com/heroku/buildpacks-procfile/issues/73
         ProcfileBuildpackError::ProcfileParsingError(parsing_error) => match parsing_error {},
         ProcfileBuildpackError::ProcfileConversionError(conversion_error) => match conversion_error
         {
             ProcfileConversionError::InvalidProcessType(libcnb_error) => {
-                log_error(
-                    "Cannot convert Procfile to CNB launch configuration",
-                    formatdoc! {"
-                        This is an unexpected internal error that occurs when a Procfile entry is not
-                        compatible with the CNB launch configuration. At the time of writing, Procfile
-                        process names are a strict subset of CNB launch process names and this should
-                        never happen.
-
-                        Please report this issue with the details below.
-
-                        Details: {libcnb_error}
-                    "},
-                );
+                build_output.error(formatdoc! {"
+                    Cannot convert Procfile to CNB launch configuration
+
+                    This is an unexpected internal error that occurs when a Procfile entry is not
+                    compatible with the CNB launch configuration. At the time of writing, Procfile
+                    process names are a strict subset of CNB launch process names and this should
+                    never happen.
+
+                    Please report this issue with the details below.
+
+                    Details: {libcnb_error}
+                "});
             }
         },
     }