Hi.
I have problem understanding why my build fails. The error tells me nothing…
Plz help 
building and signing IPA
[11:19:36] Using gulpfile /usr/local/turtle-agent/tools-public/gulpfile.js
[11:19:36] Starting ‘ios:build-and-sign-ipa’…
provisioning profile copied to home directory
done retrieving provisioning profile data
checking if teamID is present in keychain and that certificate is valid…
ensured certificate is valid
writing export-options.plist file…
created export-options.plist file
generating IPA…
[stderr] [11:20:02] ‘ios:build-and-sign-ipa’ errored after 26 s
[stderr] [11:20:02] Error: Process exited with non-zero code: 1
[stderr] at ChildProcess.child.on (/usr/local/turtle-agent/tools-public/node_modules/@expo/spawn-async/build/spawnAsync.js:39:21)
[stderr] at emitTwo (events.js:125:13)
[stderr] at ChildProcess.emit (events.js:213:7)
[stderr] at maybeClose (internal/child_process.js:927:16)
[stderr] at Socket.stream.socket.on (internal/child_process.js:348:11)
[stderr] at emitOne (events.js:115:13)
[stderr] at Socket.emit (events.js:210:7)
[stderr] at Pipe._handle.close [as _onclose] (net.js:545:12)
unable to build and sign IPA