title: Exception Thrown by TextStyle.dart Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true
body: <p>I am trying to use CupertinoApp and when I try to navigate to new screen the exception is thrown and doesn't render the title of the screen in navigationBar.</p>
  <pre><code>══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
  The following assertion was thrown building Positioned(left: 119.6, top: 51.0, right: 148.4, bottom:
  7.0):
  '
  
      package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b
      == null || a.inherit == b.inherit': is not true.
  
  Either the assertion indicates an error in the framework itself, or we should provide substantially
  more information in this error message to help you determine and fix the underlying cause.
  In either case, please report this assertion by filing a bug on GitHub:
    https://github.com/flutter/flutter/issues/new?template=BUG.md
  
  The relevant error-causing widget was:
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  
  When the exception was thrown, this was the stack:
  
      #2      TextStyle.lerp (package:flutter/src/painting/text_style.dart:936:12)
      #3      TextStyleTween.lerp (package:flutter/src/widgets/implicit_animations.dart:218:41)
      #4      Tween.transform (package:flutter/src/animation/tween.dart:262:12)
      #5      Animatable.evaluate (package:flutter/src/animation/tween.dart:55:46)
      #6      _AnimatedEvaluation.value (package:flutter/src/animation/tween.dart:89:31)
      #7      _AnimatedEvaluation.toString (package:flutter/src/animation/tween.dart:93:46)
      #8      DiagnosticsProperty.valueToString (package:flutter/src/foundation/diagnostics.dart:2740:61)
      #9      DiagnosticsProperty.toDescription (package:flutter/src/foundation/diagnostics.dart:2754:21)
      #10     TextTreeRenderer._debugRender (package:flutter/src/foundation/diagnostics.dart:1195:31)
      #11     TextTreeRenderer.render (package:flutter/src/foundation/diagnostics.dart:1128:14)
      #12     TextTreeRenderer._debugRender (package:flutter/src/foundation/diagnostics.dart:1305:39)
      #13     TextTreeRenderer.render (package:flutter/src/foundation/diagnostics.dart:1128:14)
      #14     DiagnosticsNode.toStringDeep.&lt;anonymous closure&gt; (package:flutter/src/foundation/diagnostics.dart:1748:9)
      #15     DiagnosticsNode.toStringDeep (package:flutter/src/foundation/diagnostics.dart:1755:6)
      #16     DiagnosticsNode.toString.&lt;anonymous closure&gt; (package:flutter/src/foundation/diagnostics.dart:1661:18)
      #17     DiagnosticsNode.toString (package:flutter/src/foundation/diagnostics.dart:1676:6)
      #18     Diagnosticable.toString.&lt;anonymous closure&gt; (package:flutter/src/foundation/diagnostics.dart:3110:78)
      #19     Diagnosticable.toString (package:flutter/src/foundation/diagnostics.dart:3112:6)
      #20     _StringBase._interpolate (dart:core-patch/string_patch.dart:848:19)
      #21     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4556:44)
      #22     StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4719:11)
      #23     Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
      #24     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
      #25     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4710:11)
      #26     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
      ...     Normal element mounting (21 frames)
      #47     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
      #48     MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5991:32)
      ...     Normal element mounting (53 frames)
      #101    Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
      #102    Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
      #103    RenderObjectElement.updateChildren (package:flutter/src/widgets/framework.dart:5624:32)
      #104    MultiChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:6001:17)
      #105    Element.updateChild (package:flutter/src/widgets/framework.dart:3245:15)
      #106    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
      #107    StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4719:11)
      #108    Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
      #109    BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2667:33)
      #110    WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:866:20)
      #111    RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:286:5)
      #112    SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1117:15)
      #113    SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1056:9)
      #114    SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:972:5)
      #118    _invoke (dart:ui/hooks.dart:253:10)
      #119    _drawFrame (dart:ui/hooks.dart:211:3)
      (elided 5 frames from class _AssertionError and dart:async)
  
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ Exception caught by widgets library ═══════════════════════════════════════════════════════
  The following assertion was thrown building Positioned(left: 119.6, top: 51.0, right: 148.4, bottom: 7.0):
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  
  Either the assertion indicates an error in the framework itself, or we should provide substantially more information in this error message to help you determine and fix the underlying cause.
  In either case, please report this assertion by filing a bug on GitHub:
    https://github.com/flutter/flutter/issues/new?template=BUG.md
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  When the exception was thrown, this was the stack: 
  
      #2      TextStyle.lerp (package:flutter/src/painting/text_style.dart:936:12)
      #3      TextStyleTween.lerp (package:flutter/src/widgets/implicit_animations.dart:218:41)
      #4      Tween.transform (package:flutter/src/animation/tween.dart:262:12)
      #5      Animatable.evaluate (package:flutter/src/animation/tween.dart:55:46)
      #6      _AnimatedEvaluation.value (package:flutter/src/animation/tween.dart:89:31)
      ...
  
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  ════════ (2) Exception caught by widgets library ═══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
      Another exception was thrown: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  ════════ (3) Exception caught by widgets library ═══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  ════════ (4) Exception caught by widgets library ═══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  ════════ (5) Exception caught by widgets library ═══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  ════════ (6) Exception caught by widgets library ═══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: '
  
      package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  ════════ (7) Exception caught by widgets library ═══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  ════════ (8) Exception caught by widgets library ═══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (9) Exception caught by widgets library ═══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (10) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: _TransitionableNavigationBar.renderBox should be called when building hero flight shuttles when the from and the to nav bar boxes are already laid out and painted.
  
  ════════ (11) Exception caught by widgets library ══════════════════════════════════════════════════
  _TransitionableNavigationBar.renderBox should be called when building hero flight shuttles when the from and the to nav bar boxes are already laid out and painted.
  
      'package:flutter/src/cupertino/nav_bar.dart':
      Failed assertion: line 1506 pos 7: 'box.attached'
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown:
  
       'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════ (12) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  Another exception was thrown: 
  
     
  
       'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  ════════ (13) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
      Another exception was thrown: 'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════ (14) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (15) Exception caught by scheduler library ════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: `'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.`
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  ════════ (16) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (17) Exception caught by widgets library ══════════════════════════════════════════════════
  `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not tr`ue.
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
      Another exception was thrown: 'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════ (18) Exception caught by widgets library ══════════════════════════════════════════════════
  '`package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
      Another exception was thrown: 'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════ (19) Exception caught by scheduler library ════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  ════════ (20) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════ (21) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: `'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.`
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  Another exception was thrown: 
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  ════════ (22) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════ (23) Exception caught by scheduler library ════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: `'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.`
  
  ════════ (24) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  Another exception was thrown: `'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.`
  
  ════════ (25) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: `'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.`
  
  ════════ (26) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════ (27) Exception caught by scheduler library ════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  Another exception was thrown: 
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  ════════ (28) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  Another exception was thrown: 
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════ (29) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (30) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  flutter: Black Shirt
  
  ════════ (31) Exception caught by scheduler library ════════════════════════════════════════════════
  'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (32) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (33) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (34) Exception caught by widgets library ══════════════════════════════════════════════════
  
      'package:flutter/src/widgets/framework.dart': Failed assertion: line 4264 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
  
  The relevant error-causing widget was: 
    CupertinoApp file:///Users/pranavharer/shop_app/lib/main.dart:23:18
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  
  ════════ (35) Exception caught by scheduler library ════════════════════════════════════════════════
  
      'package:flutter/src/painting/text_style.dart': Failed assertion: line 936 pos 12: 'a == null || b == null || a.inherit == b.inherit': is not true.
  
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  </code></pre>
  <p>Here is my main.dart file</p>
  <pre><code>void main() =&gt; runApp(MyApp());
  
  class MyApp extends StatelessWidget {
    // This widget is the root of your application.
    @override
    Widget build(BuildContext context) {
      final txtmul = Responsive.textMultiplier;
      MaterialLocalizations.of(context);
      return LayoutBuilder(builder: (context, constraints) {
        return OrientationBuilder(builder: (context, orientation) {
          Responsive().init(constraints, orientation);
          return ChangeNotifierProvider(
            create: (ctx)=&gt; Products(),
            child: CupertinoApp(
              title: 'Shopping',
              theme: CupertinoThemeData(
                scaffoldBackgroundColor: Colors.grey,
                barBackgroundColor: Colors.lightGreenAccent,
                primaryColor: Colors.amber,
                textTheme: CupertinoTextThemeData(
                  primaryColor: Colors.black,
                  navTitleTextStyle:  TextStyle(
                    fontFamily: 'YellowRabit',
                    fontSize: txtmul * 15,
                    color: Colors.amber,
                  ),
                  textStyle: TextStyle(
                    fontSize: Responsive.textMultiplier * 15,
                    fontFamily: 'Constantia',
                    color: Colors.brown,
                  ),
                ),
              ),
              home: ProductOverView(),
              routes: {
                ProductDetailScreen.routeName: (ctx) =&gt; ProductDetailScreen(),},
  ),
          );
        });
      });
    }
  }
  </code></pre>