Monobjc 6.0.2710.0 crashes on OS X versions prior to Mavericks

[lemonmojo]

Since upgrading to Monobjc 6.0.2710.0 any Monobjc application crashes instantly upon launch when running on any OS X version prior to Mavericks.

Here's the console output from a new application created with the Xamarin Studio Monobjc Console App Template:

MonobjcPreMountainLionTest[265:707] -[NSProcessInfo operatingSystemVersion]: unrecognized selector sent to instance 0x7b32f6e0

Unhandled Exception:
Monobjc.ObjectiveCException: -[NSProcessInfo operatingSystemVersion]: unrecognized selector sent to instance 0x7b32f6e0
  at (wrapper managed-to-native) Monobjc.ObjectiveCRuntime:BootstrapInternal (string)
  at Monobjc.ObjectiveCRuntime.Bootstrap (System.String domainToken) [0x00000] in <filename unknown>:0 
  at Monobjc.ObjectiveCRuntime.Initialize (System.String domainToken) [0x00000] in <filename unknown>:0 
  at MonobjcPreMountainLionTest.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: Monobjc.ObjectiveCException: -[NSProcessInfo operatingSystemVersion]: unrecognized selector sent to instance 0x7b32f6e0
  at (wrapper managed-to-native) Monobjc.ObjectiveCRuntime:BootstrapInternal (string)
  at Monobjc.ObjectiveCRuntime.Bootstrap (System.String domainToken) [0x00000] in <filename unknown>:0 
  at Monobjc.ObjectiveCRuntime.Initialize (System.String domainToken) [0x00000] in <filename unknown>:0 
  at MonobjcPreMountainLionTest.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0

To me it looks like 3d42143 is the culprit. Since -[NSProcessInfo operatingSystemVersion] is only available since Yosemite it can't be used on older versions. Interestingly it works just fine on a fully patched Mavericks machine. But anything below that, exhibits the crash mentioned above. My guess is that one of the recent Mavericks patches brought support for the property but it probably won't be available on a vanilla installation.

[letiemble]

Hi,

I have uploaded a new package that reverts the previous code for version
detection. My test environment has broken and I was too confident that the
method will be supported (I mis-read 10.10 and 10.0).

Let me know if you have other issues.

Laurent.

2014-12-15 17:02 GMT+01:00 Felix Deimel notifications@github.com:

Since upgrading to Monobjc 6.0.2710.0 any Monobjc application crashes
instantly upon launch when running on any OS X version prior to Mavericks.

Here's the console output from a new application created with the Xamarin
Studio Monobjc Console App Template:

MonobjcPreMountainLionTest[265:707] -[NSProcessInfo operatingSystemVersion]: unrecognized selector sent to instance 0x7b32f6e0

Unhandled Exception:
Monobjc.ObjectiveCException: -[NSProcessInfo operatingSystemVersion]: unrecognized selector sent to instance 0x7b32f6e0
at (wrapper managed-to-native) Monobjc.ObjectiveCRuntime:BootstrapInternal (string)
at Monobjc.ObjectiveCRuntime.Bootstrap (System.String domainToken) [0x00000] in :0
at Monobjc.ObjectiveCRuntime.Initialize (System.String domainToken) [0x00000] in :0
at MonobjcPreMountainLionTest.Program.Main (System.String[] args) [0x00000] in :0
[ERROR] FATAL UNHANDLED EXCEPTION: Monobjc.ObjectiveCException: -[NSProcessInfo operatingSystemVersion]: unrecognized selector sent to instance 0x7b32f6e0
at (wrapper managed-to-native) Monobjc.ObjectiveCRuntime:BootstrapInternal (string)
at Monobjc.ObjectiveCRuntime.Bootstrap (System.String domainToken) [0x00000] in :0
at Monobjc.ObjectiveCRuntime.Initialize (System.String domainToken) [0x00000] in :0
at MonobjcPreMountainLionTest.Program.Main (System.String[] args) [0x00000] in :0

To me it looks like 3d42143
3d42143
is the culprit. Since -[NSProcessInfo operatingSystemVersion] is only
available since Yosemite it can't be used on older versions. Interestingly
it works just fine on a fully patched Mavericks machine. But anything below
that, exhibits the crash mentioned above. My guess is that one of the
recent Mavericks patches brought support for the property but it probably
won't be available on a vanilla installation.

—
Reply to this email directly or view it on GitHub
#432.

[lemonmojo]

@letiemble Cool, thx!
Will take me some time to test this because I'm currently using a modified Monobjc version compiled from source.
That's because I still have issues with this line:

monobjc/libraries/Monobjc/Class.cs

Line 129 in 5ebe22a

throw new ObjectiveCException (String.Format (CultureInfo.CurrentCulture, Resources.NoClassAttributeFoundForType, type));

This causes exceptions like this one every now and then:

System.TypeInitializationException: An exception was thrown by the type initializer for remojoConnectionTypes.Web.PropertyPageWebMainController ---> Monobjc.ObjectiveCException: No ObjectiveCClass attribute found for type 'Monobjc.Class'
  at Monobjc.Class.GetAttributeName (System.Type type) [0x00000] in <filename unknown>:0 
  at (wrapper managed-to-native) Monobjc.Class:Get (string)
  at Monobjc.Class.Get (System.Type type) [0x00000] in <filename unknown>:0 
  at remojoConnectionTypes.Web.PropertyPageWebMainController..cctor () [0x00000] in <filename unknown>:0 
  --- End of inner exception stack trace ---
  at remojoConnectionTypes.Web.WebPropertyPages..ctor () [0x00000] in <filename unknown>:0 
  at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (System.Reflection.MonoCMethod,object,object[],System.Exception&)
  at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0 

I have already looked over all of my projects and there's no class that should be exposed to the Objective-C runtime that doesn't have a ObjectiveCClass attribute.
What I did is replace the line with return "Class"; which seems to get rid of the issue.
I can't say for certain that it completely fixes the issue because it's a rather rare bug, but I haven't seen it ever since making the change.

[lemonmojo]

@letiemble Just tested 6.0.2744.0 (using your Mono 3.12.0 x64 package) and the NSProcessInfo bug is gone.