"raco pollen render" fails sporadically

[primer]

I'm having an issue with getting a failure with "raco pollen render" in directory mode using a poly source file.  See below for a command line history demonstrating the behavior.

The call usually fails but sometimes succeeds.  I have not been able to find a reliable workaround to the issue.  Sometimes deleting the "compiled" directory seems to help but not always.  The files are taken from the fourth pollen tutorial, and both txt and html output targets have worked on occasion but not consistently.

If I'm reading the source code correctly, the error coming is out of a function called render-batch and the proximate cause is that there are two source paths and three output paths.

FWIW I'm using racket 7.9.

/d/data/prj/racket/scribble/goodexamples/multi-output2$ ll
total 17
-rw-r--r-- 1 mbk None 6524 Nov 13 12:52 bashlog.txt
drwxr-xr-x 1 mbk None    0 Nov 13 12:49 compiled
-rw-r--r-- 1 mbk None  180 Nov 13 12:49 cv.html
-rw-r--r-- 1 mbk None  104 Nov 13 13:54 cv.poly.pm
-rw-r--r-- 1 mbk None  364 Nov 13 12:42 pollen.rkt
-rw-r--r-- 1 mbk None   83 Nov 13 12:49 template.txt
-rw-r--r-- 1 mbk None   83 Nov 13 13:54 template.txt.p
/d/data/prj/racket/scribble/goodexamples/multi-output2$ rm -r compiled/
/d/data/prj/racket/scribble/goodexamples/multi-output2$ rm cv.html
/d/data/prj/racket/scribble/goodexamples/multi-output2$ rm template.txt
/d/data/prj/racket/scribble/goodexamples/multi-output2$ raco pollen render -d -t txt .
pollen: rendering generated pagetree for directory D:\data\prj\racket\scribble\goodexamples\multi-output2\
pollen: D:\data\prj\racket\scribble\goodexamples\multi-output2\cv.poly.pm
pollen: D:\data\prj\racket\scribble\goodexamples\multi-output2\template.txt.p
/d/data/prj/racket/scribble/goodexamples/multi-output2$ raco pollen render -f -t txt .
pollen: rendering generated pagetree for directory D:\data\prj\racket\scribble\goodexamples\multi-output2\
pollen: rendering /cv.poly.pm as txt
pollen: rendered /cv.txt (386 ms)
pollen: rendering /template.txt.p
pollen: rendered /template.txt (0 ms)
/d/data/prj/racket/scribble/goodexamples/multi-output2$ raco pollen render -f -t html .
for-each: all lists must have same size
  first list length: 2
  other list length: 3
  procedure: #<procedure:...ollen/render.rkt:210:28>