1. Summarise the issue (what were doing, what went wrong?)

I just tried to run a test script:

  darcs-test -t issue1234.sh

I got this result:

 darcs-test: darcs-test: canonicalizePath: does not exist (No such file 
or directory)

2. What behaviour were you expecting instead?

I would expect this diagnostic to print out the path that's having 
trouble constructing, so that I have an idea of how to fix it. Without 
more detail, I have to resort to guessing to fix it. 

3. What darcs version are you using? (Try: darcs --exact-version)

    2.9.7 (+ 49 patches)

I discovered in my case that the problem had nothing to with the format 
of the test file, as I assumed... it was having trouble having the 
related darcs binary to use. I could workaround it like this:

  darcs-test --darcs=/home/mark/bin/darcs -t issue2271-disable-patch-
index.sh

It actually appears that the code in harness/test.sh intends to return a 
better diagnostic if darcs can't be found:

  "No darcs specified or found nearby. Perhaps --darcs 
`pwd`/dist/build/darcs/darcs"

However, it appears than an uncaught exception is being thrown before 
the code can get that far.