F# in Monodevelop: Stack traces when opening .fsx file

Question

Extension .fsx stands for an Fsharp File that will be compiled to an executable.

Cannot open .fsx files in Monodevelop (from Ubuntu maverick repo). TargetInvocationException , FileNameNotResolved

Please see screenshot on flickr

When I rename the file to .fs (Fsharp script file) then it can be opened.

Actually, I have three questions:

1. Why am I getting this stack trace? I just imported/added the file and it is indeed in the solution folder.
2. How to fix monodevelop?
3. How can I get the text of the stack trace into a log file?

Answer 1

This error used to happen with older versions of F#. Are you using November 2010 F# update ?

(To give some more details - There is nothing wrong with the fsx file, but the language service fails when loading. The problem is that the F# IntelliSense service running in MonoDevelop cannot locate some referenced assembly. This is done by calling the F# compiler and F# compiler contained error (in IntelliSense code when on Mono) where it tries to load wrong file eg System instead of System.dll - the November 2010 update should fix this).

If updating F# doesn't resolve the problem, can you send a repro to the F# open source mailing list: http://groups.google.com/group/fsharp-opensource ?

Answer 2

Upgrade your Mono. Ubuntu 10.10 has an old version of Mono that seems to cause a lot of problems with fsi.exe . And it is sloooow . Considering F#, at least, Debian (upstream) and Ubuntu need to upgrade 2.6.7 to one of the 2.8.x releases soon!

I've been playing around with this version of Mono 2.8.2 and my programs are behaving much better. (I haven't synced up the cli executable and MonoDevelop yet, but just running /new/path/mono fsc.exe or whatever, so far, but I'm a lot happier.)