Assert failed: block != nullptr in system.xml.xmlserializer.reflectiononly.tests

[runfoapp]

In rolling build 1902387 several xml tests failed with this assert on net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1200.Arm64.Open

https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-heads-main-a9fafacc48a0407da6/System.Xml.XmlSerializer.ReflectionOnly.Tests/1/console.8e657ff8.log?%3Fhelixlogtype%3Dresult

[15:38:16] dbug: Running /usr/libexec/PlistBuddy -c "Print CFBundleIdentifier" /tmp/helix/working/C09F09A7/w/9A090886/e/System.Xml.XmlSerializer.ReflectionOnly.Tests.app/Contents/Info.plist
[15:38:16] dbug: Process PlistBuddy exited with 0
[15:38:16] dbug: 
[15:38:16] dbug: Running /usr/libexec/PlistBuddy -c "Print UIRequiredDeviceCapabilities" /tmp/helix/working/C09F09A7/w/9A090886/e/System.Xml.XmlSerializer.ReflectionOnly.Tests.app/Contents/Info.plist
[15:38:16] dbug: Process PlistBuddy exited with 1
assertion failed [block != nullptr]: BasicBlock requested for unrecognized address
(BuilderBase.h:550 block_for_offset)
./xharness-runner.apple.sh: line 154: 21578 Trace/BPT trap: 5       (core dumped) dotnet exec "$XHARNESS_CLI_PATH" "$@"
Removing empty log files:

The same failure also appears in two other Xml tests:
https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-heads-main-a9fafacc48a0407da6/System.Xml.XPath.XmlDocument.Tests/1/console.af8a69cb.log?%3Fhelixlogtype%3Dresult

https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-heads-main-a9fafacc48a0407da6/System.Xml.RW.WrappedReader.Tests/1/console.196a8295.log?%3Fhelixlogtype%3Dresult

Runfo Tracking Issue: system.xml.xmlserializer.reflectiononly.tests work item

Build	Definition	Kind	Run Name	Console	Core Dump	Test Results	Run Client
1920416	runtime-extra-platforms	PR 72925	net7.0-tvOS-Release-arm64-Mono_Release-OSX.1100.Amd64.AppleTV.Open	console.log			runclient.py
1902387	runtime-extra-platforms	Rolling	net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1200.Arm64.Open	console.log			runclient.py

Build Result Summary

Day Hit Count	Week Hit Count	Month Hit Count
0	1	2

Tagging subscribers to 'os-maccatalyst': @steveisok, @akoeplinger
See info in area-owners.md if you want to be subscribed.

Issue Details

---

In rolling build 1902387 several xml tests failed with this assert on net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1200.Arm64.Open

https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-heads-main-a9fafacc48a0407da6/System.Xml.XmlSerializer.ReflectionOnly.Tests/1/console.8e657ff8.log?%3Fhelixlogtype%3Dresult

[15:38:16] dbug: Running /usr/libexec/PlistBuddy -c "Print CFBundleIdentifier" /tmp/helix/working/C09F09A7/w/9A090886/e/System.Xml.XmlSerializer.ReflectionOnly.Tests.app/Contents/Info.plist
[15:38:16] dbug: Process PlistBuddy exited with 0
[15:38:16] dbug: 
[15:38:16] dbug: Running /usr/libexec/PlistBuddy -c "Print UIRequiredDeviceCapabilities" /tmp/helix/working/C09F09A7/w/9A090886/e/System.Xml.XmlSerializer.ReflectionOnly.Tests.app/Contents/Info.plist
[15:38:16] dbug: Process PlistBuddy exited with 1
assertion failed [block != nullptr]: BasicBlock requested for unrecognized address
(BuilderBase.h:550 block_for_offset)
./xharness-runner.apple.sh: line 154: 21578 Trace/BPT trap: 5       (core dumped) dotnet exec "$XHARNESS_CLI_PATH" "$@"
Removing empty log files:

The same failure also appears in two other Xml tests:
https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-heads-main-a9fafacc48a0407da6/System.Xml.XPath.XmlDocument.Tests/1/console.af8a69cb.log?%3Fhelixlogtype%3Dresult

https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-heads-main-a9fafacc48a0407da6/System.Xml.RW.WrappedReader.Tests/1/console.196a8295.log?%3Fhelixlogtype%3Dresult

Runfo Tracking Issue: system.xml.xmlserializer.reflectiononly.tests work item

Build	Definition	Kind	Run Name	Console	Core Dump	Test Results	Run Client
1902387	runtime-extra-platforms	Rolling	net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1200.Arm64.Open	console.log			runclient.py

Build Result Summary

Day Hit Count	Week Hit Count	Month Hit Count
1	1	1

Author:	runfoapp[bot]
Assignees:	-
Labels:	area-Serialization, untriaged, os-maccatalyst, arm64
Milestone:	-

[steveisok]

/cc @agocke

I do not believe this is a MacCatalyst issue as I think the crash is coming from dotnet itself:

assertion failed [block != nullptr]: BasicBlock requested for unrecognized address (BuilderBase.h:550 block_for_offset).

I asked on FR yesterday to reboot the machines, but I don't think this solves the problem. What's interesting is it only happens on a handful of machines per CI run.

[danmoseley]

I don't know where 'BasicBlock requested for unrecognized address' is coming from. It appears to be some library we are using -- is this using any chk libraries? Putting in mono-vm .

[steveisok]

This is just a guess, but the assert may be

runtime/src/coreclr/jit/block.h

Line 1673 in 39d82c9

assert(block != nullptr);

For mobile runs, the first part that deals with xharness / launching an app is dotnet w/ a coreclr runtime. I believe the crash is happening there.