Really do avoid reporting [object Object]

_Especially_ in the error code path.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

GitForWindowsHelper/index.js

@@ -33,7 +33,7 @@ module.exports = async function (context, req) {
             && req.body.comment.body.startsWith('/')) return ok(await slashCommand(context, req))
     } catch (e) {
         context.log(e)
-        return withStatus(500, undefined, e.toString('utf-8'))
+        return withStatus(500, undefined, e.message || JSON.stringify(e, null, 2))
     }
 
     try {
@@ -46,7 +46,7 @@ module.exports = async function (context, req) {
             && req.body.workflow_job.labels[1] === 'ARM64') return ok(await selfHostedARM64Runners(context, req))
     } catch (e) {
         context.log(e)
-        return withStatus(500, undefined, e.toString('utf-8'))
+        return withStatus(500, undefined, e.message || JSON.stringify(e, null, 2))
     }
 
     try {
@@ -56,7 +56,7 @@ module.exports = async function (context, req) {
             && req.body.action === 'completed') return ok(await cascadingRuns(context, req))
     } catch (e) {
         context.log(e)
-        return withStatus(500, undefined, e.toString('utf-8'))
+        return withStatus(500, undefined, e.message || JSON.stringify(e, null, 2))
     }
 
     context.log("Got headers")

GitForWindowsHelper/slash-commands.js

@@ -347,7 +347,7 @@ module.exports = async (context, req) => {
                         status: 'completed',
                         conclusion: 'failure',
                         output: {
-                            text: e.toString()
+                            text: e.message || JSON.stringify(e, null, 2)
                         }
                     }
                 )
@@ -455,7 +455,7 @@ module.exports = async (context, req) => {
                         status: 'completed',
                         conclusion: 'failure',
                         output: {
-                            text: e.toString()
+                            text: e.message || JSON.stringify(e, null, 2)
                         }
                     }
                 )