From 730fa6e6d2b86fa856c1afa06c9f7bb1171be9c7 Mon Sep 17 00:00:00 2001
From: ascopes <73482956+ascopes@users.noreply.github.com>
Date: Sun, 4 Feb 2024 11:26:06 +0000
Subject: [PATCH] GH-86: Fix exception causes being omitted from Maven output

---
 .../ascopes/protobufmavenplugin/AbstractGenerateMojo.java     | 4 +++-
 .../protobufmavenplugin/source/ProtoSourceResolver.java       | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/main/java/io/github/ascopes/protobufmavenplugin/AbstractGenerateMojo.java b/src/main/java/io/github/ascopes/protobufmavenplugin/AbstractGenerateMojo.java
index 9f41ba5f..14aeda30 100644
--- a/src/main/java/io/github/ascopes/protobufmavenplugin/AbstractGenerateMojo.java
+++ b/src/main/java/io/github/ascopes/protobufmavenplugin/AbstractGenerateMojo.java
@@ -264,7 +264,9 @@ public void execute() throws MojoExecutionException, MojoFailureException {
         throw new MojoExecutionException("Protoc invocation failed");
       }
     } catch (ResolutionException | IOException ex) {
-      throw new MojoFailureException(this, ex.getMessage(), ex.getMessage());
+      var mojoFailureException = new MojoFailureException(this, ex.getMessage(), ex.getMessage());
+      mojoFailureException.initCause(ex);
+      throw mojoFailureException;
     }
   }
 
diff --git a/src/main/java/io/github/ascopes/protobufmavenplugin/source/ProtoSourceResolver.java b/src/main/java/io/github/ascopes/protobufmavenplugin/source/ProtoSourceResolver.java
index f14fbee4..0f019479 100644
--- a/src/main/java/io/github/ascopes/protobufmavenplugin/source/ProtoSourceResolver.java
+++ b/src/main/java/io/github/ascopes/protobufmavenplugin/source/ProtoSourceResolver.java
@@ -95,8 +95,10 @@ public Collection<ProtoFileListing> createProtoFileListings(
     }
 
     if (!exceptions.isEmpty()) {
+      var causeIterator = exceptions.iterator();
       var ex = new IOException("Failed to create listings asynchronously");
-      exceptions.forEach(ex::addSuppressed);
+      ex.initCause(causeIterator.next());
+      causeIterator.forEachRemaining(ex::addSuppressed);
       throw ex;
     }