NuGet allows (and I currently use) package locations that include spaces. Both within the nuget.config file and on the command line, this is as simple as quoting the path (this is already done in the config file because the source path is an attribute on an XML node).

Working with a package source I set up for my team's internal libraries and trying to use @dsyme's F# script from here (and subsequently @moodmosaic's fork of it), I get back the error Couldn't get package details for package X on ["C:\Path"]. when specifying source C:\Path With Spaces\.

Given a directory named Test Folder in my c-drive, I've tried the following formats:

Paket.Dependencies.Install """
    source "C:\Test Folder"
    nuget fscheck 0.9.4
"""

Paket.Dependencies.Install "
    source \"C:\Test Folder\"
    nuget fscheck 0.9.4
"

and

Paket.Dependencies.Install "
    source C:\Test\ Folder
    nuget fscheck 0.9.4
"

I have tried creating a symlink to the directory, such that the symlink can be accessed without spaces in the path; this works with no problems.