Observed in Beta. See: https://cxserver-beta.wmflabs.org/v1
Stack trace:
{
"name": "cxserver",
"hostname": "deployment-sca01",
"pid": 14,
"level": 50,
"message": "500: internal_error",
"stack": "TypeError: Cannot read property key of undefined\n at /srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/src/app.js:126:56\n at Layer.handle [as handle_request] (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/layer.js:95:5)\n at next (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/route.js:137:13)\n at next (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/route.js:131:14)\n at next (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/route.js:131:14)\n at next (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/route.js:131:14)\n at next (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/route.js:131:14)\n at next (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/route.js:131:14)\n at next (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/route.js:131:14)\n at Route.dispatch (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/route.js:112:3)\n at Layer.handle [as handle_request] (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/layer.js:95:5)\n at /srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/index.js:281:22\n at param (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/index.js:354:14)\n at param (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/index.js:365:14)\n at Function.process_params (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/index.js:410:3)\n at next (/srv/deployment/cxserver/deploy-cache/revs/a8e7abf16ba896656ba4f144b96691a5ba9a5a06/node_modules/express/lib/router/index.js:275:10)",
"status": 500,
"type": "internal_error",
"detail": "Cannot read property key of undefined",