Las2dem creates broken outputs due to temp file error while processing in parallel.

[Andrew Neil Sager]

Recently while using las2dem as part of an ALS processing pipeline I noted that for a handful of tiles the output DEMs would be corrupted. After isolating two of the offending files it became apparent that the error was repeatable and only occurred during parallel processing with the -cores argument. I have attached the -vv log output from the command I was attempting to run, the critical portion being 

ERROR: cannot re-open file 'temp.00031.tmp' for read in SRbufferRows

Oddly, changing the file names appears to prevent the error from happening. What I think might be happening is that the parallel processing is creating a temp file with the same name for each of the files causing one to be overwritten before processing is complete. The temp file names are likely related to the base file name, causing the file name change to prevent the error from occurring.

I have the offending files if you would like to reproduce the error, but they exceed the 24mb attachment size limit. 

[rapid...@gmail.com]

Hi Andrew,

thanks for the detailed description of the problem and the log file.

Yes, this is probably because of the way we are creating the temp files.

Can you please send us your test data and we will try to reproduce and fix this problem.

Please send the files best by download link or as attachment in a private mail.

Cheers,

Jochen @rapidlasso

[Andrew Neil Sager]

Hi Jochen,

Here's a link to a zip of the two files https://drive.google.com/file/d/1zcEzQWdC3aEHjt4XoA1P9P_2ge4RP3VB/view?usp=sharing

Very Respectfully,

Andrew Sager