Use the older version of onesignal-cordova-plugin if you have in zip format than use it,

• Cordova platform add -
  $ /data/build-server/cordova/6.5.0/bin/cordova platform add /data/build-server/cordova/platforms/ios/4.4.0
  Adding ios project…
• Cordova plugin add -
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add mobi.monaca.plugins.Monaca
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-plugin-whitelist@1.3.1
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-plugin-device-motion@1.2.5
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-plugin-device-orientation@1.0.7
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-plugin-geolocation@2.4.3
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-plugin-network-information@1.3.3
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-plugin-splashscreen@4.0.3
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-plugin-device@1.1.6
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-custom-config@2.0.3
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add https://github.com/danwilson/google-analytics-plugin
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add cordova-plugin-inappbrowser@1.7.1
  $ /data/build-server/cordova/6.5.0/bin/cordova plugin add https://github.com/OneSignal/OneSignal-Cordova-SDK
  Fetching plugin "https://github.com/OneSignal/OneSignal-Cordova-SDK" via git clone
  Repository "https://github.com/OneSignal/OneSignal-Cordova-SDK" checked out to git ref “master”.
  Installing “onesignal-cordova-plugin” for ios
  Failed to install ‘onesignal-cordova-plugin’:Error: pod: Command failed with exit code 1
  at ChildProcess.whenDone (/private/tmp/monaca/5a443b9de7888507048b456b/project/platforms/ios/cordova/node_modules/cordova-common/src/superspawn.js:169:23)
  at emitTwo (events.js:87:13)
  at ChildProcess.emit (events.js:172:7)
  at maybeClose (internal/child_process.js:827:16)
  at Socket.<anonymous> (internal/child_process.js:319:11)
  at emitOne (events.js:77:13)
  at Socket.emit (events.js:169:7)
  at Pipe._onclose (net.js:486:12)

Remove DerivedData files…
Change Xcode Version to 8

• postBuild -
  Remove working directories…
  Build Error: Error: Sandbox Exec Error: [ Error: pod: Command failed with exit code 1
  ]