ANDROID build error - what could this be?

What could this error be?

Plugin doesn't support this project's cordova-android version. cordova-android: 6.3.0, failed version requirement: 
      <6.3.0
Skipping 'cordova-plugin-compat' for android
Plugin dependency "es6-promise-plugin@4.2.2" already fetched, using that version.
Dependent plugin "es6-promise-plugin" already installed on android.
Subproject Path: CordovaLib
Adding cordova-plugin-geofence to package.json
Saved plugin info for "cordova-plugin-geofence" to config.xml
(node:1) UnhandledPromiseRejectionWarning: Error: ≈    at Function.Module._resolveFilename (module.js:547:15)
    at Function.Module._load (module.js:474:25)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Context.requireCordovaModule (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/hooks/Context.js:77:12)
    at module.exports (/usr/src/app/plugins/cordova-plugin-add-swift-support/src/add-swift-support.js:23:34)
    at runScriptViaModuleLoader (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/hooks/HooksRunner.js:188:18)
    at runScript (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/hooks/HooksRunner.js:164:16)
    at /usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/hooks/HooksRunner.js:132:20
    at _fulfilled (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/q/q.js:787:54)
(node:1) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:1) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
$ cordova platform add android --no-fetch success
$ cordova build android --release -- --keystore=android.keystore --storePassword=***** --alias=fultonstreet --password=*****
WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
(node:1) UnhandledPromiseRejectionWarning: Error: Cannot find module '../cordova/platform_metadata'
    at Function.Module._resolveFilename (module.js:547:15)
    at Function.Module._load (module.js:474:25)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Context.requireCordovaModule (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/hooks/Context.js:77:12)
    at module.exports (/usr/src/app/plugins/cordova-plugin-add-swift-support/src/add-swift-support.js:23:34)
    at runScriptViaModuleLoader (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/hooks/HooksRunner.js:188:18)
    at runScript (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/hooks/HooksRunner.js:164:16)
    at /usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/hooks/HooksRunner.js:132:20
    at _fulfilled (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/q/q.js:787:54)
(node:1) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:1) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

What is your ionic info output?