# Change in local package does not take effect unless Julia restart

**URL:** <https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612>\
**Category:** New to Julia\
**Tags:** question\
**Created:** [December 23, 2019, 9:00am UTC](https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612 "2019-12-23T09:00:10Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![Sijun](https://avatars.discourse-cdn.com/v4/letter/s/b2d939/32.png) [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Post date:** [December 23, 2019, 9:00am UTC](https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612/1 "2019-12-23T09:00:10Z")

</div>

Suppose I am in a primary environment say, environment/v1.3.  
Now I take the following steps to create a package as a local git repo and do some tests:

```julia
1) ] generate TestPkg
2) git init/add -A/commit in TestPkg directory
3) ] add TestPkg
4) using TestPkg
5) Try TestPkg.greet()
6) Make some changes on TestPkg.greet()
7) git update on TestPkg
8) ] update TestPkg
9) Try TestPkg.greet() and observe the change takes effect

```

This is fine and as expected. However if I create a new project environment and repeat the same steps in the local environment, the change on the package source file does not take effect even after git update. It needs Julia restart.

I could not find any clue as to why this is so from Julia doc and Pkg.jl doc.  
Am I missing anything?

---

<div class="post-metadata">

**Author:** ![mauro3](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mauro3/32/292_2.png) [@mauro3](https://discourse.julialang.org/u/mauro3)\
**Post date:** [December 23, 2019, 9:29am UTC](https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612/2 "2019-12-23T09:29:22Z")

</div>

Are you using Revise:

> **[GitHub - timholy/Revise.jl: Automatically update function definitions in a...](https://github.com/timholy/Revise.jl)**
>
> Automatically update function definitions in a running Julia session - GitHub - timholy/Revise.jl: Automatically update function definitions in a running Julia session

?

---

<div class="post-metadata">

**Author:** ![Sijun](https://avatars.discourse-cdn.com/v4/letter/s/b2d939/32.png) [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Post date:** [December 23, 2019, 10:06am UTC](https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612/3 "2019-12-23T10:06:26Z")

</div>

Sure I am. However, in case that the package is git-controlled, in order for any change to take effect, it needs `git commit` followed by `] update package` (actually this is in line with the statement in Pkg.jl doc). In this case Revise isn’t triggered ( **but why?** ). **Also, this observation only holds as long as I am in the primary environment**. If I change to a local custom environment, I have to restart Julia to see the change each time. Neither Revise nor git commit helps in this case.

On the contrary, any package in dev folder in a primary or custom environment is under Revise’s surveillance if they are in LOAD\_PATH (as announced) but strangely for packages in dev folder, git commit does not let any change take effect in the absence of Revise.

---

<div class="post-metadata">

**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [December 23, 2019, 10:19am UTC](https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612/4 "2019-12-23T10:19:02Z")

</div>

> [@Sijun](#):
>
> However if I create a new project environment and repeat the same steps in the local environment

Can you spell out your steps in detail, including how you’re starting Julia & Revise?

---

<div class="post-metadata">

**Author:** ![Sijun](https://avatars.discourse-cdn.com/v4/letter/s/b2d939/32.png) [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Post date:** [December 23, 2019, 10:48am UTC](https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612/5 "2019-12-23T10:48:44Z")

</div>

Thank you for help.

Julia 1.3.0 / Revise v2.3.2

startup.jl is as follows:

```julia
using Distributed

@everywhere push!(LOAD_PATH, "D:/work/julia")
@everywhere push!(LOAD_PATH, "D:/work/julia/test/")
@everywhere push!(LOAD_PATH, "D:/work/julia/test/MyPkg")
@everywhere push!(LOAD_PATH, "D:/work/julia/test/MyPkg/src")

atreplinit() do repl
    try
        @eval using Revise
        @async Revise.wait_steal_repl_backend()
    catch
    end
end

```

Step 1.

```julia
shell> cd test
D:\work\julia\test

```

Step 2.

```julia
(v1.3) pkg> generate MyPkg
Generating project MyPkg:
    MyPkg\Project.toml
    MyPkg/src/MyPkg.jl

```

Step 3.

```julia
shell> git init ./MyPkg
Initialized empty Git repository in D:/work/julia/test/MyPkg/.git/

```

Step 4.

```julia
shell> cd MyPkg
D:\work\julia\test\MyPkg

shell> git add -A

shell> git commit -m"init"
[master (root-commit) a323639] init
 2 files changed, 9 insertions(+)
 create mode 100644 Project.toml
 create mode 100644 src/MyPkg.jl

```

Step 5.

```julia
shell> cd ..
D:\work\julia\test

(v1.3) pkg> add MyPkg
[ Info: resolving package identifier `MyPkg` as a directory at `D:\work\julia\test\MyPkg`.
   Cloning git-repo `MyPkg`
  Updating git-repo `D:/work/julia/test/MyPkg`
  Updating git-repo `D:/work/julia/test/MyPkg`
 Resolving package versions...
  Updating `C:\Users\sijun.cho\.julia\environments\v1.3\Project.toml`
  [48f60d83] + MyPkg v0.1.0 #master (MyPkg)
  Updating `C:\Users\sijun.cho\.julia\environments\v1.3\Manifest.toml`
  [48f60d83] + MyPkg v0.1.0 #master (MyPkg)

```

Step 6.

```julia
julia> using MyPkg
[Info: Precompiling MyPkg [48f60d83-e34d-427a-8afc-fdeaa2472ade]

julia> MyPkg.greet()
Hello World!

```

Step 7.

```julia
module MyPkg

#greet() = print("Hello World!")
greet() = print("Hello Everyone!")

end # module

```

Step 8.

```julia
julia> using MyPkg

julia> MyPkg.greet() # No change, although paths are pushed to LOAD_PATH hoping Revise will catch
Hello World!

```

Step 9.

```julia
shell> cd test/MyPkg
D:\work\julia\test\MyPkg

shell> git add -A
warning: LF will be replaced by CRLF in src/MyPkg.jl.
The file will have its original line endings in your working directory

shell> git commit -m"upd"
[master 20157e1] upd
 1 file changed, 1 insertion(+), 1 deletion(-)

(v1.3) pkg> update MyPkg
  Updating registry at `C:\Users\sijun.cho\.julia\registries\General`
  Updating git-repo `https://github.com/JuliaRegistries/General.git`
  Updating git-repo `D:/work/julia/test/MyPkg`
 Resolving package versions...
  Updating `C:\Users\sijun.cho\.julia\environments\v1.3\Project.toml`
  [48f60d83] ~ MyPkg v0.1.0 #master (MyPkg)
  Updating `C:\Users\sijun.cho\.julia\environments\v1.3\Manifest.toml`
  [48f60d83] ~ MyPkg v0.1.0 #master (MyPkg)

```

Step 10.

```julia
julia> using MyPkg

julia> MyPkg.greet() # now see the change
Hello Everyone!

```

If I `] activate myenv` and follow the above steps, things are worsen. Even `git commit` & `] update package ` no longer works; Julia should be restarted.

---

<div class="post-metadata">

**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [December 24, 2019, 12:39pm UTC](https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612/6 "2019-12-24T12:39:06Z")

</div>

The short answer is that you should `dev MyPkg` rather than `add MyPkg`.

In greater detail: when you say `]add MyPkg`,the package manager makes a copy of the files that you created in `D:\work\julia\test` and stashes them in your `.julia/packages` directory. Right after the `add` you’ll probably get something like this:

```julia
julia> pathof(MyPkg)
"/home/tim/.julia/packages/MyPkg/o1AMF/src/MyPkg.jl"

```

This is the path that Revise uses as the definition of this package. Consequently any changes to files in `D:\work\julia\test` do not get tracked.

Even if you edited the files in `.julia/packages/MyPkg/`, Revise wouldn’t track them. That’s because `add` means “use a version-controlled release of a given package.” If you’re making changes, you’re no longer using a version-controlled release. Indeed, in recent Julia versions all the source files in `.julia/packages` have write permissions disabled. (Your editor might “helpfully” offer to change them to writable, but you should decline such offers of assistance.)

Revise will, however, follow changes from `add` to `dev`. If you make a mistake and `]add MyPkg` instead, you can fix it by saying `]dev MyPkg` and any changes you’ve already made will be incorporated. That’s because Revise will use the files in your `.julia/packages/MyPkg` directory as a reference against which to compare the changes.

---

<div class="post-metadata">

**Author:** ![Sijun](https://avatars.discourse-cdn.com/v4/letter/s/b2d939/32.png) [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Post date:** [December 24, 2019, 1:16pm UTC](https://discourse.julialang.org/t/change-in-local-package-does-not-take-effect-unless-julia-restart/32612/7 "2019-12-24T13:16:44Z")

</div>

Thank you very much for the clear explanation. Now I have come to understand how Revise works.