# FYI : small patch to build Slicer on Arch Linux
**URL:** https://discourse.slicer.org/t/fyi-small-patch-to-build-slicer-on-arch-linux/23961
**Category:** Development
**Created:** [June 20, 2022, 11:50am UTC](https://discourse.slicer.org/t/fyi-small-patch-to-build-slicer-on-arch-linux/23961 "2022-06-20T11:50:30Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@chir.set](https://discourse.slicer.org/u/chir.set)
#### Post date: [June 20, 2022, 11:50am UTC](https://discourse.slicer.org/t/fyi-small-patch-to-build-slicer-on-arch-linux/23961/1 "2022-06-20T11:50:31Z")
Building Slicer at 5ecfcc37a51 failed on Arch Linux, with QSignalSpy not found message.
This patch is required for a successful build :
```auto
$ git diff
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5158d8759..8aa04ccd8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -608,6 +608,7 @@ endif()
# This component is needed for building VTK
if(UNIX AND NOT APPLE)
list(APPEND Slicer_REQUIRED_QT_MODULES X11Extras)
+ list(APPEND Slicer_REQUIRED_QT_MODULES Test)
endif()
find_package(Qt5 COMPONENTS Core QUIET)
```
Just FYI, in case it would need a fix somewhere, if it’s not Arch specific.
---
### Author:  [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)
#### Post date: [June 20, 2022, 12:09pm UTC](https://discourse.slicer.org/t/fyi-small-patch-to-build-slicer-on-arch-linux/23961/2 "2022-06-20T12:09:01Z")
Thank you @chir.set. This looks to me related to the following PR
>
>
> Qt modules Concurrent and Test are explicit requirements for CTK. This
> commit a…dds these as requirements for Slicer too.
The bottom line is that we need to conciliate the Slicer Qt requirements with those of CTK as @jcfr suggested in the PR. I’ll try to give more priority to solve this issue so these types of errors don’t occur in the future
---
### Author:  [@jamesobutler](https://discourse.slicer.org/u/jamesobutler)
#### Post date: [June 20, 2022, 1:09pm UTC](https://discourse.slicer.org/t/fyi-small-patch-to-build-slicer-on-arch-linux/23961/3 "2022-06-20T13:09:14Z")
Here’s the corresponding issue report:
>
>
> \## Summary
>
> fail to build master branch:
> \`\`\`
> /build/3dslicer-git/src/3dslice…r/Base/QTCore/qSlicerExtensionsManagerModel.cxx:31:10: fatal error: QSignalSpy: No such file or directory
> 31 | #include \
> | ^ ~~~~~~~~~~~
> compilation terminated.
> \`\`\`
> see also the complete build log \[here\](https://github.com/Slicer/Slicer/files/8934955/log.txt.tar.gz). You could jump to the line 72251 for the error messages.
>
> Maybe we forget to add \`testlib\` according to Qt official \[doc\](https://doc.qt.io/qt-5/qsignalspy.html)?
>
> \## Steps to reproduce
>
> I build 3dslicer with this \[PKGBUILD\](https://github.com/archlinuxcn/repo/blob/8c62f8b6aca24634780329e42c49286236610ebf/archlinuxcn/3dslicer-git/PKGBUILD) on ArchLinux with minor modification. I use
> \`\`\`
> make -C "build" VERBOSE=1
> \`\`\`
> to print more information.
>
> \## Expected behavior
>
>
>
> \## Environment
> \- Slicer version: the master branch, date 20220619
> \- Operating system: ArchLinux
---
### Author:  [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)
#### Post date: [June 20, 2022, 2:08pm UTC](https://discourse.slicer.org/t/fyi-small-patch-to-build-slicer-on-arch-linux/23961/4 "2022-06-20T14:08:51Z")
@chir.set, @jamesobutler [Slicer/Slicer#6437](https://github.com/Slicer/Slicer/pull/6165) and [Slicer/Slicer#6165](https://github.com/Slicer/Slicer/issues/6437) point to similar problems but are not exactly the same. One refers to a compilation error when building slicer and the other refers to a possible configuration error on CTK when building the superbuild. Sorry for the confusion.