`lttng` test fails on Fedora

[omajid]

See https://github.com/redhat-developer/dotnet-regular-tests/runs/8078697017?check_suite_focus=true:

# Standard Output:
Executing /__w/dotnet-regular-tests/dotnet-regular-tests/lttng/test.sh with arguments 6.0.8 in working directory /__w/dotnet-regular-tests/dotnet-regular-tests/lttng
== Starting lttng session
Session my-session created.
Traces will be output to /tmp/my-session/trace
ust context vpid added to all channels
ust event DotNETRuntime:RuntimeInformationStart created in channel channel0
Tracing started for session my-session
== Creating new console application

Welcome to .NET 6.0!
---------------------
SDK Version: 6.0.108

----------------
Installed an ASP.NET Core HTTPS development certificate.
To trust the certificate run 'dotnet dev-certs https --trust' (Windows and macOS only).
Learn about HTTPS: https://aka.ms/dotnet-https
----------------
Write your first app: https://aka.ms/dotnet-hello-world
Find out what's new: https://aka.ms/dotnet-whats-new
Explore documentation: https://aka.ms/dotnet-docs
Report issues and find source on GitHub: https://github.com/dotnet/core
Use 'dotnet --help' to see available commands or visit: https://aka.ms/dotnet-cli
--------------------------------------------------------------------------------------
The template "Console App" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on /tmp/my-session/console/console.csproj...
  Determining projects to restore...
  Restored /tmp/my-session/console/console.csproj (in 186 ms).
Restore succeeded.

== Ending lttng session
Waiting for data availability
Tracing stopped for session my-session
Destroying session my-session..
Session my-session destroyed
Exit Code: 1
# Standard Error:
Error:  Cannot open any trace for reading.

Error:  opening trace "�$�5" for reading.

Error:  none of the specified trace paths could be opened.

[omajid]

@tmds do you have some cycles to dig into this?

[tmds]

Does this fail anywhere other than Fedora Rawhide?

[omajid]

37 too, I think. Doesn't fail on 35 or 36. I haven't tested on any other distribution family.

[tmds]

Unless this is urgent, I'll take a look when I upgrade my laptop to Fedora 37, which will happen in the next one or two weeks.

[tmds]

I ran this test on Fedora 37. There is nothing wrong with the .NET side of things: lttng-sessiond receives the a DotNETRuntime:RuntimeInformationStart event.

lttng-sessiond also creates the trace folder at the expected location of /tmp/my-session/trace/ust/uid/1000/64-bit.

babeltrace is not happy with what's in that folder, and spits out the error messages we see in the log:

Error:  Cannot open any trace for reading.

Error:  opening trace "�$�5" for reading.

Error:  none of the specified trace paths could be opened.

The version numbers on the packages seem to indicate not much changed between f36 and f37:

lttng-tools                     2.13.4-1.fc36
lttng-ust                       2.13.1-2.fc36
babeltrace                      1.5.8-9.fc36

lttng-tools.x86_64              2.13.7-3.fc37                
lttng-ust.x86_64                2.13.3-3.fc37  
babeltrace.x86_64               1.5.8-12.fc37  

[tmds]

Current state: test passes on Fedora 38, and fails with Fedora Rawhide (39).

[tmds]

The test is now crashing on Fedora 38:

: Executing /tmp/tmp.Dkr0O4tRps/dotnet-regular-tests/lttng/test.sh with arguments 8.0.0-rc.2.23418.14 in working directory /tmp/tmp.Dkr0O4tRps/dotnet-regular-tests/lttng
== Starting lttng session
Session my-session created.
Traces will be output to /tmp/my-session/trace
ust context vpid added to all channels
ust event DotNETRuntime:RuntimeInformationStart created in channel channel0
Tracing started for session my-session
== Creating new console application
/tmp/tmp.Dkr0O4tRps/dotnet-regular-tests/lttng/test.sh: line 46: 134211 Segmentation fault      (core dumped) dotnet new console -o $TEST_FOLDER/console
Process Exit Code: 139

[ayakael]

What is best practice for mitigating lttng-ust 2.13 and up issues? On Alpine we've been removing and touching libcoreclrtraceptprovider.so but I'm not sure that's the best approach anymore.

[tmds]

What is best practice for mitigating lttng-ust 2.13 and up issues?

I have not investigated this further.

I have not used LTTNG with .NET in a very long time, and no one else seems to have noticed except our CI...

Do you know what potentially is the root cause?

[kiran-1992n]

See https://github.com/redhat-developer/dotnet-regular-tests/runs/8078697017?check_suite_focus=true:

# Standard Output:
Executing /__w/dotnet-regular-tests/dotnet-regular-tests/lttng/test.sh with arguments 6.0.8 in working directory /__w/dotnet-regular-tests/dotnet-regular-tests/lttng
== Starting lttng session
Session my-session created.
Traces will be output to /tmp/my-session/trace
ust context vpid added to all channels
ust event DotNETRuntime:RuntimeInformationStart created in channel channel0
Tracing started for session my-session
== Creating new console application

Welcome to .NET 6.0!
---------------------
SDK Version: 6.0.108

----------------
Installed an ASP.NET Core HTTPS development certificate.
To trust the certificate run 'dotnet dev-certs https --trust' (Windows and macOS only).
Learn about HTTPS: https://aka.ms/dotnet-https
----------------
Write your first app: https://aka.ms/dotnet-hello-world
Find out what's new: https://aka.ms/dotnet-whats-new
Explore documentation: https://aka.ms/dotnet-docs
Report issues and find source on GitHub: https://github.com/dotnet/core
Use 'dotnet --help' to see available commands or visit: https://aka.ms/dotnet-cli
--------------------------------------------------------------------------------------
The template "Console App" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on /tmp/my-session/console/console.csproj...
  Determining projects to restore...
  Restored /tmp/my-session/console/console.csproj (in 186 ms).
Restore succeeded.

== Ending lttng session
Waiting for data availability
Tracing stopped for session my-session
Destroying session my-session..
Session my-session destroyed
Exit Code: 1
# Standard Error:
Error:  Cannot open any trace for reading.

Error:  opening trace "�$�5" for reading.

Error:  none of the specified trace paths could be opened.

LTTNG is not generating trace files on RHEL 8.8. Getting same trace .
babeltrace is not happy with what's in that folder - There are no trace files generated in the folder.
Any Suggestions Appreciated.