"ls" only matches files relative to the current directory

[nominolo]

If you use ls in a rule, it won't pick up paths outside of the current directory (unless you use "..").

This seems to be a bug from the Glob library. E.g., try this

$ cd ~/tmp
$ touch aaa
$ ghci
> import System.FilePath.Glob
> globDir1 (compile "/home/me/tmp/aaa") ""   -- use your home dir

This should find the given file, but doesn't.

[batterseapower]

The code sample you give shouldn't work since I think the arguments to globDir1 are the wrong way around. Try this:

globDir1 (compile "*") "/Users/myusername"

It works as expected.

[batterseapower]

Can you give me an example of how ls fails?

[nominolo]

Well, the Glob library itself may not be at fault, but one could argue that openshake is. The use case is the following:

When I compile a file with GHC it goes on to look through a number of search paths to find source files and dependencies, etc. These paths are usually outside the current project directory. I want to properly model all of these dependencies, because if the contents of these directories change it may affect my project.

The way globDir is currently used inside openshake I am not able to specify a dependency on a file where I know the absolute path. I can only refer to it by computing the right amount of "../".

[batterseapower]

OK now I understand.

So you expect that globDir1 ((compile dir) fp) should return getDirectoryContents dir for any fp. This does indeed seem like reasonable behaviour for the glob package.

[nominolo]

Well, yes, although even more general. The fp argument should really only be used to resolve relative patterns (e.g., foo*), but absolute filepath patterns should be allowed, too, i.e., globDir1 (compile (dir </> "*")) fp should also return the contents of dir.

Interestingly, this doesn't work in regular Unix tools, either. E.g., find . -name '/home/me/tmp/*' doesn't return anything. So, perhaps the question is whether the Glob library is the right tool in all cases.

[batterseapower]

My intuition is that (globDir1 pat dir) is the same thing as (cd dir && echo pat), in which case what you want to do makes sense.