Ignored 2335 lines with invalid format: ERROR: No stack counts found

[ylluminate]

When executing the commands and generating a seemingly valid result, I get an error:

$ sudo sample PID -file ~/tmp/(date +"%Y-%m-%d_%H.%M.%S")-sample.txt -fullPaths 1
Sampling process 198 for 1 second with 1 millisecond of run time between samples
Sampling completed, processing symbols...
Sample analysis of process 35264 written to file /Users/user/tmp/2023-02-20_02.40.14-sample.txt

$ python stackcollapse-sample.py /Users/user/tmp/2023-02-20_02.40.14-sample.txt > /Users/user/tmp/2023-02-20_02.40.14-sample_collapsed.txt

$ flamegraph.pl /Users/user/tmp/2023-02-20_02.40.14-sample_collapsed.txt > /Users/user/tmp/2023-02-20_02.40.14-sample_collapsed_flamegraph.svg
Ignored 2335 lines with invalid format
ERROR: No stack counts found

Any thoughts on what may be going wrong or how to diagnose this further?

[brc7]

Hey there!

Sorry that this took me so long to look into. It seems there were quite a few parsing bugs in the tool. We didn't originally catch these because we had very limited, structured use cases.

I've patched the parser and run this on a couple different applications (Safari, Python interpreter, a few C++ binaries with known contents) and the flamegraph output is as expected.

Please try again, and let me know if this fixes your issue.

[ylluminate]

Thank you so much for looking into this. I attempted to generate a test sample again (2 seconds of WindowServer) and it produced this sample file.

When I then executed stackcollapse-sample.py it produced a zero byte file:

$ sudo sample "WindowServer" -file ~/tmp/(date +"%Y-%m-%d_%H.%M.%S")-sample.txt -fullPaths 2
Password:
Sampling process 196 for 2 seconds with 1 millisecond of run time between samples
Sampling completed, processing symbols...
Sample analysis of process 196 written to file /Users/user/tmp/2023-03-02_03.11.43-sample.txt

$ sudo python stackcollapse-sample.py /Users/user/tmp/2023-03-02_03.11.43-sample.txt > /Users/user/tmp/2023-03-02_03.11.43-sample_collapsed.txt

$ ls -lh
628 KB 2023-03-02_03.11.48 2023-03-02_03.11.43-sample.txt
  0 B  2023-03-02_03.12.36 2023-03-02_03.11.43-sample_collapsed.txt

[brc7]

Odd, I can't reproduce the issue.

$ sudo sample "WindowServer" -file windowserver-sample.txt -fullPaths 2 
Password:
Sampling process 162 for 2 seconds with 1 millisecond of run time between samples
Sampling completed, processing symbols...
Sample analysis of process 162 written to file windowserver-sample.txt
$ python stackcollapse-sample.py windowserver-sample.txt > windowserver-collapsed.txt 
$ wc -c windowserver-sample.txt windowserver-collapsed.txt 
  139017 windowserver-sample.txt
  412792 windowserver-collapsed.txt
  551809 total

I also tried running on the sample file you provided, and the output of stackcollapse-sample.py and flamegraph.pl seem correct.

windowserver-collapsed.txt

Can you try dumping the output of sample to a directory that doesn't require sudo permissions? I wasn't able to produce collapsed stacks when I tried reading from /Users/* on MacOS 12.3.

[brc7]

Closing as this seems to be solved. If you're still experiencing this issue, feel free to comment and we'll reopen / resolve.

[ylluminate]

Yeah, unfortunately it's still happening for me. I just don't know what to do at this point since I'm tied up heavily in another project. I'll see if I can figure out a way to debug it further or such at some point hopefully.