# Julia 1.3 and IJulia -- how to find Julia 1.3 as kernel?

**URL:** <https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689>\
**Category:** General Usage\
**Created:** [November 30, 2019, 11:44am UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689 "2019-11-30T11:44:14Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [November 30, 2019, 11:44am UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/1 "2019-11-30T11:44:14Z")

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I just removed Julia 1.2 and installed Julia 1.3 + renamed `v1.2` to `v1.3` in `.julia\environments` + did `]instantiate` and updated packages.

When I fire up `IJulia`, `Julia 1.2` shows up as the only available kernel (together with `Python 3`).

How can I:

- make Julia 1.3 available as kernel, and
- remove Julia 1.2 as available kernel

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**Author:** ![baggepinnen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/baggepinnen/32/693_2.png) [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Post date:** [November 30, 2019, 12:03pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/2 "2019-11-30T12:03:29Z")

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`] build IJulia`

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**Author:** ![sylvaticus](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sylvaticus/32/203883_2.png) [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Post date:** [November 30, 2019, 12:04pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/3 "2019-11-30T12:04:55Z")

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for the first one just type from a julia 1.3 prompt:

```julia
] add IJulia
build IJulia

```

For removing the old kernel I woult have fist removed the IJulia package from the 1.2 Julia before removing Julia. As you have already removed Julia 1.2, try from Julia 1.3 to remove the IJulia package (`] rm IJulia`) before adding it.

EDIT: The solution from @baggepinnen should suffix

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<div class="post-metadata">

**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [November 30, 2019, 12:19pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/4 "2019-11-30T12:19:10Z")

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Following your advice, both kernels Julia 1.2 and Julia 1.3 are available. (I’d like to remove Julia 1.2 from the pop-up menu, though).

However, when I choose Julia 1.3, I get the following error message:

```julia
Error Starting Kernel
Traceback (most recent call last):
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\tornado\web.py", line 1699, in _execute
    result = await result
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\tornado\gen.py", line 742, in run
    yielded = self.gen.throw(*exc_info) # type: ignore
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\notebook\services\sessions\handlers.py", line 72, in post
    type=mtype))
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\tornado\gen.py", line 735, in run
    value = future.result()
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\tornado\gen.py", line 742, in run
    yielded = self.gen.throw(*exc_info) # type: ignore
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\notebook\services\sessions\sessionmanager.py", line 88, in create_session
    kernel_id = yield self.start_kernel_for_session(session_id, path, name, type, kernel_name)
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\tornado\gen.py", line 735, in run
    value = future.result()
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\tornado\gen.py", line 742, in run
    yielded = self.gen.throw(*exc_info) # type: ignore
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\notebook\services\sessions\sessionmanager.py", line 101, in start_kernel_for_session
    self.kernel_manager.start_kernel(path=kernel_path, kernel_name=kernel_name)
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\tornado\gen.py", line 735, in run
    value = future.result()
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\tornado\gen.py", line 209, in wrapper
    yielded = next(result)
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\notebook\services\kernels\kernelmanager.py", line 168, in start_kernel
    super(MappingKernelManager, self).start_kernel(**kwargs)
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\jupyter_client\multikernelmanager.py", line 110, in start_kernel
    km.start_kernel(**kwargs)
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\jupyter_client\manager.py", line 259, in start_kernel
    **kw)
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\jupyter_client\manager.py", line 204, in _launch_kernel
    return launch_kernel(kernel_cmd, **kw)
  File "C:\Users\user_name\.julia\conda\3\lib\site-packages\jupyter_client\launcher.py", line 138, in launch_kernel
    proc = Popen(cmd, **kwargs)
  File "C:\Users\user_name\.julia\conda\3\lib\subprocess.py", line 709, in __init__
    restore_signals, start_new_session)
  File "C:\Users\user_name\.julia\conda\3\lib\subprocess.py", line 997, in _execute_child
    startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the file specified

```

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<div class="post-metadata">

**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [November 30, 2019, 3:55pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/5 "2019-11-30T15:55:01Z")

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> [@BLI](#):
>
> (I’d like to remove Julia 1.2 from the pop-up menu, though.)

Do `using IJulia; IJulia.kerneldir()` which will tell you the location of all of Jupyter’s kernel-specification files. You can simply delete any you don’t want.

In particular, you can remove the Julia 1.2 kernelspec with

```julia
using IJulia
rm(joinpath(IJulia.kerneldir(), "julia-1.2"), recursive=true)

```

> [@BLI](#):
>
> However, when I choose Julia 1.3, I get the following error message:

A `FileNotFoundError` from Python usually means that you moved Julia after installing the kernel specification, so that Jupyter now doesn’t know where to find `julia.exe`. Re-run `build IJulia` in Julia 1.3.

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<div class="post-metadata">

**Author:** ![non-Jedi](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/non-jedi/32/3645_2.png) [@non-Jedi](https://discourse.julialang.org/u/non-Jedi)\
**Post date:** [November 30, 2019, 4:07pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/6 "2019-11-30T16:07:33Z")

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It’s probably better to just use `jupyter kernelspec remove julia-1.2` instead.

Edit: Although I guess that doesn’t work when julia installs its own private jupyter via Conda.jl.

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**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [November 30, 2019, 5:58pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/7 "2019-11-30T17:58:55Z")

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I used `IJulia.kerneldir()` and deleted the Julia 1.2 kernel manually. Next, I did `]build IJulia`, and now it seems to work.

Thanks!

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**Author:** ![ctkelley](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ctkelley/32/10684_2.png) [@ctkelley](https://discourse.julialang.org/u/ctkelley)\
**Post date:** [April 21, 2020, 1:39pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/8 "2020-04-21T13:39:48Z")

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I’m having the same problem and am completely stuck. I had some old notebooks for Julia 1.1. I erased 1.1 a few months ago and am now on 1.4.1. The old notebooks can’t find the new kernel. The new notebooks ( created wiht Julia 1.4.1 ) work fine. I did

1. update and build IJulia
2. use IJulia.kerneldir and deleted the 1.1 kernel
3. changed the kernel to 1.4.1 in the pulldown menu
4. did ]rm IJulia; add IJulia; build IJulia

I’m getting “Kernel starting please wait” for a while. Then the notebook briefly says that I’m connected, but then I see a popup that says

Connection failed: a connection could not be established …

I don’t know enough about python to mess with conda. What should I do now?

I’m running a Mac with the latest OS. This is a personal device, so there are no firewall issues.

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**Author:** ![ctkelley](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ctkelley/32/10684_2.png) [@ctkelley](https://discourse.julialang.org/u/ctkelley)\
**Post date:** [April 21, 2020, 5:15pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/9 "2020-04-21T17:15:50Z")

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Erased .julia and started over. Problem solved!

Any idea why I had to do this?

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**Author:** ![ageron](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ageron/32/15465_2.png) [@ageron](https://discourse.julialang.org/u/ageron)\
**Post date:** [June 23, 2020, 8:55pm UTC](https://discourse.julialang.org/t/julia-1-3-and-ijulia-how-to-find-julia-1-3-as-kernel/31689/10 "2020-06-23T20:55:12Z")

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You can use this [Colab notebook template](https://colab.research.google.com/github/ageron/julia_notebooks/blob/master/Julia_Colab_Notebook_Template.ipynb) which supports any Julia version (from 0.7.0 to the latest).

FYI, here’s how it works: the kernel specified in the .ipynb file is named “julia”. After installing IJulia, the code renames the kernel from “julia-\<specific version\>” to “julia”. That’s it.

Hope this helps.