If you try to parse the code "(do\n", the parser fails because of the missing parenthesis. However, the error message references column -1, which isn't a real place in the file.
$ fennel repro.txt
repro.txt:2:-1 Parse error: expected closing delimiter )
...
I would have expected something like 2:0.
I'm not sure if this is a very important issue, but I did encounter it in
fennel-ls. My workaround in fennel-ls is to use (math.max col 0) instead of
col, which changes it to the nearest valid location.
Fixed in f80b947.