```
$ man -Thtml 1 man >man.html
Calling `pnmcut 150 479 485 151 < /tmp/groff-page-umqrKe | pnmcrop -quiet | pnmtopng -background rgb:f/f/f -transparent rgb:f/f/f > grohtml-196661.png
' returned status 256
Calling `pnmcut 150 819 371 102 < /tmp/groff-page-umqrKe | pnmcrop -quiet | pnmtopng -background rgb:f/f/f -transparent rgb:f/f/f > grohtml-196662.png
' returned status 256
Calling `pnmcut 200 416 264 88 < /tmp/groff-page-umqrKe | pnmcrop -quiet | pnmtopng -background rgb:f/f/f -transparent rgb:f/f/f > grohtml-196663.png
' returned status 256
```

This successfully generates `man.html`, but fails to generate the embedded `.png` files.

I've tracked this problem down to the `chdir()` in the `display()` function in `man.c`. It changes the cwd to `/usr/share/man` (on my system at least). This prevents the `pnmtopng ... >grohtml-196661.png` command from working, since that has no write access to `/usr/share/man`, and of course it shouldn't be writing the file there anyway.

Simply commenting out the `chdir()` makes this particular case work. But I don't know what else that will break.

Note: the pnmcut/pnmcrop/pnmtopng pipeline gets run by `groff`, which in turn gets run by `man`.