Could not open MPEG file: mpgtmp.mpg, because it never existed.

The latest versions of mencoder, mplayer and the 2.2b version of mpeg_stat return this error, running on either Debian 10 or Ubuntu 18.04.04:

mpeg_stat -- MPEG Analyzer for MPEG I video streams (version 2.2b)
MPlayer 1.3.0 (Debian), built with gcc-8 (C) 2000-2016 MPlayer Team
MEncoder 1.3.0 (Debian), built with gcc-8 (C) 2000-2016 MPlayer Team
It seems we found all programs :)...continuing
______________________________________________
Converting input.avi
Transcoding video:   done
Transcoding audio:   done
Could not open MPEG file:  mpgtmp.mpg

Usage:  mpeg_stat [options] [mpeg_file]
Options:
  -quiet: 		 Turn off output of frame types/matricies as encountered
  -verify: 		 Do more work to help assure the validity of the stream
			 (slows processing somewhat)
  -start N: 		 Begin collection at frame N (first frame is 1)
  -end N: 		 End collection at frame N (end >= start)
  -histogram file:	 Put detailed histograms into file
  -qscale file: 	 Put qscale information into file
  -size file: 		 Write individual frame type and size into file
  -offsets file: 	 Write high level header offsets into file
  -block_info file:	 Put macroblock usage into file
  -dct 			 Puts decoded DCT info into block file
  -rate file: 		 Put instantaneous rate information in file
  -ratelength N: 	 Measure bitrate per N frames, not one second's worth
  -syslog file: 	 Store parsing of systerm layer into file
  -userdata file: 	 Store user data information into file
  -time: 		 Measure time to decode frames
  -all file: 		 Put all information into files with basename file

A single dash (-) may be used to denote standard in/out in place of a filename.

mpeg_stat -- MPEG Analyzer for MPEG I video streams (version 2.2b)

Writing offset information to stat.tmp
Error using mpeg_stat ... see error above
Removing temporary files

Update: it seems to work fine in a Ubuntu 12.04 VM, so I was able to get a file converted.