# Fresh Arch Linux install: UndefVarError: backend not defined

**URL:** <https://discourse.julialang.org/t/fresh-arch-linux-install-undefvarerror-backend-not-defined/41245>\
**Category:** New to Julia\
**Created:** [June 12, 2020, 5:55am UTC](https://discourse.julialang.org/t/fresh-arch-linux-install-undefvarerror-backend-not-defined/41245 "2020-06-12T05:55:25Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![fusion809](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fusion809/32/6080_2.png) [@fusion809](https://discourse.julialang.org/u/fusion809)\
**Post date:** [June 12, 2020, 5:55am UTC](https://discourse.julialang.org/t/fresh-arch-linux-install-undefvarerror-backend-not-defined/41245/1 "2020-06-12T05:55:25Z")

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I just created a new Arch Linux install, and while on my old Arch Linux install my Julia scripts run fine, on this fresh install [this one](https://github.com/fusion809/julia-scripts/blob/master/SLE/airy-linear.jl) keeps returning the error:

```julia
UndefVarError: backend not defined

Stacktrace:
 [1] pygui(::Bool) at /home/fusion809/.julia/packages/PyPlot/XHEG0/src/init.jl:221
 [2] top-level scope at /data/GitHub/mine/math/julia-scripts/SLE/airy-linear.jl:21
 [3] macro expansion at ./util.jl:175 [inlined]
 [4] top-level scope at ./In[7]:1

```

Naturally, you may be asking whether it’s a missing dependency issue, which was my first thought too. But I have:

- `python-matplotlib`
- `python-pyqt5`
- `python-gobject`
- `qt5`

installed, I also have this ~/.matplotlibrc file:

```python
font.family : serif
font.serif : Times, Palatino, New Century Schoolbook, Bookman, Computer Modern Roman
font.sans-serif : Helvetica, Avant Garde, Computer Modern Sans serif
font.cursive : Zapf Chancery
font.monospace : Courier, Computer Modern Typewriter

text.usetex : true
rcParams['qt5']

```

. If it is relevant, I am trying to execute this Julia script through JupyterLab (i.e. I have a cell in JupyterLab that runs: `@time include("airy-linear.jl")`). Any one have any ideas how I can rectify this issue? I am stumped at this point.

---

<div class="post-metadata">

**Author:** ![fusion809](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fusion809/32/6080_2.png) [@fusion809](https://discourse.julialang.org/u/fusion809)\
**Post date:** [June 12, 2020, 6:07am UTC](https://discourse.julialang.org/t/fresh-arch-linux-install-undefvarerror-backend-not-defined/41245/2 "2020-06-12T06:07:57Z")

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Oops, never mind. I just had to restart JupyterLab in order for newly installed packages (the ones I listed) to fix the issue I had.