Modifying and testing a registered package in a directory outside of .julia

I am in the process of editing a file in a standard package (SpecialFunctions). For better or worse, I’ve already done my work using the standard git procedure, but outside the .julia directory structure. I can’t find any advice on how to test my updated branch of the package. I would appreciate help as I’ve already created havoc with some kludgy guesses.

To elaborate, I have cloned , started a new branch on my local machine ~/Julia/Testing, and pushed this to . In my julia session, I’d like to use my new branch rather than the registered master branch.

Is there a way to toggle between versions of packages, in the way a python user would call import mytestdir/special vs import scipy.special? I have a feeling the solution lies in Pkg.init(), but there isn’t enough documentation there for me to follow. Also it seems I’d have to keep pushing changes to my git-hub repo; it would be more convenient to test before making commits, I’d think.

I’ve found rather late in the day. From this I gather that I should be doing my work all within julia, although as a git tyro, this feels even more likely to lead to workflow problems.

Thanks in advance for any help.

I did a workflow video here:

Notice that Julia packages are just Github repos. So you can Pkg.checkout("MyPackage") and now you’re on master, do your stuff, push to your remote, Pkg.test("MyPackage"), and then"MyPackage") to go back to the release version. That’s why I think it’s easiest to just work from .julia/v0.x/MyPackage.

Or symlink it there.


I tried that, but git was unhappy, complaining about a detached HEAD. I’ll try more carefully. Thanks.

I made an issue related to this on Juleps a few months ago:

Really? I was under the impression, that Julia packages are git repos and github is just the default sharing platform.

I don’t know if this may be too dirty, but since you have a copy of your repository in Github, you might change your local copy of METADATA inside ~/.julia, so that your link to the “SpecialFunctions” package points to your fork of the package, instead of the original one.

You may find the file with the target url in ~.julia/v0.X/METADATA/SpecialFunctions/url (with “X” equal to the version of Julia you are using - 0.6 if you are working with the latest released version).

Then, if I’m not wrong, Pkg.update() should update that package to your fork. I have not tested that myself, so I’m not really sure if this works or it would break…

Yes, that is correct. I wrote that down incorrectly.

Thanks for the suggestion, but is this syntax depricated? I find

MethodError: no method matching add(::String, ::String)
Closest candidates are:
add(::AbstractString, ::VersionNumber…) at pkg/pkg.jl:117

[1] include_string(::String, ::String) at ./loading.jl:515

Thanks, that was very helpful! GitKraken was a sanity-saver!

Dear Chris,

I’m new to Julia (have had previous experience with C, C++, Java, JavaScript, Python).

I’m attempting to modify HTTP.jl, to allow websocket client connections with self-signed certificates (and therefore not attempt to validate certificates).

I have followed your instructions, made a fork of HTTP.jl.

However, both the fork and the registered package show that most of the source code has been commented out/ placed within nested multi-line strings. However, when I attempt to access the same package by following VSCode definition tracing (Go to definition), the multi-line strings are gone.

Is there something that I’m missing here, like a pre-processing step?

I’d be grateful if you could look at the open function in HTTP.jl, which is the function I want to modify.

Sorry if this appears to be a naive question!


Seems like you might’ve had a merge error?