Could not find an option with short name "-r"

[mattmattox]

FormatException: Could not find an option with short name "-r".
#0 Parser._validate (package:args/src/parser.dart:309)
#1 Parser._handleAbbreviation (package:args/src/parser.dart:194)
#2 Parser._parseAbbreviation (package:args/src/parser.dart:185)
#3 Parser.parse (package:args/src/parser.dart:85)
#4 ArgParser.parse (package:args/src/arg_parser.dart:335)
#5 run (package:linkcheck/linkcheck.dart:206)
#6 main. (file:///drone/src/src/bin/linkcheck.dart:11)
#7 main. (file:///drone/src/src/bin/linkcheck.dart:9)
#8 _rootRun (dart:async/zone.dart:1426)
#9 _CustomZone.run (dart:async/zone.dart:1328)
#10 _runZoned (dart:async/zone.dart:1861)
#11 runZonedGuarded (dart:async/zone.dart:1849)
#12 main (file:///drone/src/src/bin/linkcheck.dart:9)
#13 _delayEntrypointInvocation. (dart:isolate-patch/isolate_patch.dart:295)
#14 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192)