use official recommendation for parallel job output handling

Author: diegomarquezp

.github/workflows/verify.sh

@@ -26,13 +26,15 @@ cat module_list
 (echo "<project><modelVersion>4.0.0</modelVersion><groupId>temp</groupId><artifactId>temp</artifactId><version>1.0</version><packaging>pom</packaging><modules>"; cat module_list; echo "</modules></project>") > pom.xml
 cat pom.xml
 
-# test compilation
+# use generated pom to test compilation
 mvn clean compile -T 1.5C -Dmaven.testSkip=true -Denforcer.skip -fae --fail-at-end 2>&1 | tee out
 cat out | grep 'rev20' | grep 's]' | { grep 'FAILURE' || true; } > errors
 if [[ $(cat errors | wc -l) -gt 0 ]]; then
 	echo "Compilation errors found in the following libraries:"
 	cat errors
 	# send to GH output
-	echo "failed_libraries=$(cat errors | tr '\n' ',')" > "${GITHUB_OUTPUT}"
+	if [[ -f "${GITHUB_OUTPUT}" ]]; then
+	  echo "failed_libraries_${starting_letter}=$(cat errors | tr '\n' ',')" > "${GITHUB_OUTPUT}"
+	fi
 fi
 echo "No compilation errors found"

.github/workflows/verify.yaml

@@ -18,7 +18,33 @@ jobs:
         letter: ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
       fail-fast: false
     outputs:
-      failed_libraries: ${{ steps.compile.outputs.failed_libraries }}
+      # follows official example from https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/passing-information-between-jobs#using-job-outputs-in-a-matrix-job
+      failed_libraries_a: ${{ steps.compile.outputs.failed_libraries_a }}
+      failed_libraries_b: ${{ steps.compile.outputs.failed_libraries_b }}
+      failed_libraries_c: ${{ steps.compile.outputs.failed_libraries_c }}
+      failed_libraries_d: ${{ steps.compile.outputs.failed_libraries_d }}
+      failed_libraries_e: ${{ steps.compile.outputs.failed_libraries_e }}
+      failed_libraries_f: ${{ steps.compile.outputs.failed_libraries_f }}
+      failed_libraries_g: ${{ steps.compile.outputs.failed_libraries_g }}
+      failed_libraries_h: ${{ steps.compile.outputs.failed_libraries_h }}
+      failed_libraries_i: ${{ steps.compile.outputs.failed_libraries_i }}
+      failed_libraries_j: ${{ steps.compile.outputs.failed_libraries_j }}
+      failed_libraries_k: ${{ steps.compile.outputs.failed_libraries_k }}
+      failed_libraries_l: ${{ steps.compile.outputs.failed_libraries_l }}
+      failed_libraries_m: ${{ steps.compile.outputs.failed_libraries_m }}
+      failed_libraries_n: ${{ steps.compile.outputs.failed_libraries_n }}
+      failed_libraries_o: ${{ steps.compile.outputs.failed_libraries_o }}
+      failed_libraries_p: ${{ steps.compile.outputs.failed_libraries_p }}
+      failed_libraries_q: ${{ steps.compile.outputs.failed_libraries_q }}
+      failed_libraries_r: ${{ steps.compile.outputs.failed_libraries_r }}
+      failed_libraries_s: ${{ steps.compile.outputs.failed_libraries_s }}
+      failed_libraries_t: ${{ steps.compile.outputs.failed_libraries_t }}
+      failed_libraries_u: ${{ steps.compile.outputs.failed_libraries_u }}
+      failed_libraries_v: ${{ steps.compile.outputs.failed_libraries_v }}
+      failed_libraries_w: ${{ steps.compile.outputs.failed_libraries_w }}
+      failed_libraries_x: ${{ steps.compile.outputs.failed_libraries_x }}
+      failed_libraries_y: ${{ steps.compile.outputs.failed_libraries_y }}
+      failed_libraries_z: ${{ steps.compile.outputs.failed_libraries_z }}
     steps:
       - uses: actions/setup-java@v3
         with: