Add error tracing to execution failures and log to specified trace file

Author: sebastianrath

.github/workflows/workflow.yml

@@ -97,9 +97,14 @@ jobs:
         uses: actionforge/action@6635019c96dcd6b3e018df654473a547471338a5 # v0.14.5
         env:
           LICENSE: ${{ matrix.license }}
+          ACT_TRACE_FILE: /tmp/actrun-trace.log
         with:
           runner-path: ${{ github.workspace }}/actrun
           graph-file: build-test-publish.act
           inputs: ${{ toJson(inputs) }}
           secrets: ${{ toJson(secrets) }}
-          matrix: ${{ toJson(matrix) }}
+          matrix: ${{ toJson(matrix) }}
+
+      - name: Dump error trace
+        if: failure()
+        run: cat /tmp/actrun-trace.log 2>/dev/null || echo "No trace file"

core/executions.go

@@ -1,6 +1,8 @@
 package core
 
 import (
+	"fmt"
+	"os"
 	"sync"
 
 	"github.com/actionforge/actrun-cli/utils"
@@ -112,6 +114,12 @@ func (n *Executions) Execute(outputPort OutputId, ec *ExecutionState, err error)
 	}
 
 	if err != nil {
+		if traceFile := os.Getenv("ACT_TRACE_FILE"); traceFile != "" {
+			if f, ferr := os.OpenFile(traceFile, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644); ferr == nil {
+				fmt.Fprintf(f, "TRACE: node '%s' (%s) port '%s' error: %v\n", nodeID, nodeName, dest.Port, err)
+				f.Close()
+			}
+		}
 		return err
 	}