# CMake Error: VTK::nlohmannjson

**URL:** https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170
**Category:** Development
**Created:** [January 17, 2025, 4:23pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170 "2025-01-17T16:23:06Z")
**Posts on this page:** 10
**Page:** 1

<div class="post-metadata">

### Author: ![2xB](https://discourse.vtk.org/user_avatar/discourse.vtk.org/2xb/32/7543_2.png) [@2xB](https://discourse.vtk.org/u/2xB)
#### Post date: [January 17, 2025, 4:23pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/1 "2025-01-17T16:23:06Z")

</div>

Since a few days we get

```auto
CMake Error at /usr/lib64/cmake/vtk/VTK-targets.cmake:553 (set_target_properties):
  The link interface of target "VTK::nlohmannjson" contains:
    nlohmann_json::nlohmann_json
  but the target was not found. Possible reasons include:
    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.

```

in multiple Fedora 40-based CI pipelines (edit: a test using Fedora 41 shows the same issue). Last time it worked was on 04.01., first time I know it broke was on 14.01… One public project using such a pipeline is [GitHub - KATRIN-Experiment/Kassiopeia: Simulation of electric and magnetic fields and particle tracking](https://github.com/KATRIN-Experiment/Kassiopeia) ).

A quick look did not exhibit any changes w.r.t. VTK or any related package in the Fedora package registry. Since we are not using `nlohmannjson` (or `nlohmann_json`) directly, this however seems to be a VTK bug. Therefore the question: Is this known or does it have an obvious fix? Manually also installing the Fedora package `json-devel` is not solving the issue.

Potentially related to [nlohmann::json and VTK's public API](https://discourse.vtk.org/t/nlohmann-json-and-vtks-public-api/15131) .

---

<div class="post-metadata">

### Author: ![jaswantp](https://discourse.vtk.org/user_avatar/discourse.vtk.org/jaswantp/32/10046_2.png) [@jaswantp](https://discourse.vtk.org/u/jaswantp)
#### Post date: [January 17, 2025, 4:28pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/2 "2025-01-17T16:28:18Z")

</div>

This is being looked into. Until a fix is in, I belieive you can workaround by using external nlohmann json library with `VTK_MODULE_USE_EXTERNAL_VTK_nlohmannjson=ON` cmake flag.

---

<div class="post-metadata">

### Author: ![2xB](https://discourse.vtk.org/user_avatar/discourse.vtk.org/2xb/32/7543_2.png) [@2xB](https://discourse.vtk.org/u/2xB)
#### Post date: [January 17, 2025, 4:56pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/3 "2025-01-17T16:56:18Z")

</div>

Thank you very much for the quick response. The flag does however not fix it and I get

```auto
CMake Warning:
  Manually-specified variables were not used by the project:

    VTK_MODULE_USE_EXTERNAL_VTK_nlohmannjson

```

Is there an issue in an issue tracker somewhere on this? I know that this is not [https://gitlab.kitware.com/vtk/vtk/-/issues/19574](https://gitlab.kitware.com/vtk/vtk/-/issues/19574) since my issue is a CMake issue and that issue is a compile-time issue.

---

<div class="post-metadata">

### Author: ![dgobbi](https://discourse.vtk.org/user_avatar/discourse.vtk.org/dgobbi/32/18_2.png) [@dgobbi](https://discourse.vtk.org/u/dgobbi)
#### Post date: [January 17, 2025, 5:33pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/4 "2025-01-17T17:33:32Z")

</div>

This is using the default fedora 40 package, vtk-9.2.6-14.fc40? Issue #19574 is specific to vtk-9.4, so no, it couldn’t be related.

@opoplawski might know what changes might have occurred between -04 and -14.

---

<div class="post-metadata">

### Author: ![2xB](https://discourse.vtk.org/user_avatar/discourse.vtk.org/2xb/32/7543_2.png) [@2xB](https://discourse.vtk.org/u/2xB)
#### Post date: [January 17, 2025, 5:45pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/5 "2025-01-17T17:45:45Z")

</div>

This did not break between -01 and -14, that’s the weird thing. The CI used -14 both before it broke ( [KSWriteASCII: Fix header & improve output · KATRIN-Experiment/Kassiopeia@06a85ec · GitHub](https://github.com/KATRIN-Experiment/Kassiopeia/actions/runs/12268568841/job/34230625254) ) and after it broke ( [Documentation: Fix 'docker tag' example · KATRIN-Experiment/Kassiopeia@07a79a5 · GitHub](https://github.com/KATRIN-Experiment/Kassiopeia/actions/runs/12763639333/job/35574380192) ). Internally, we have more pipeline runs available and looking at the closest two from before and after it broke, these are the differences in package versions:

> **Difference in package versions between working and broken system**
>
> ```auto
> R-CRAN-MASS.x86_64
> <7.3.63-1.fc40.copr8462472
> >7.3.64-1.fc40.copr8471837
> R-CRAN-curl.x86_64
> <6.0.1-1.fc40.copr8264073
> >6.1.0-1.fc40.copr8478517
> R-CRAN-evaluate.noarch
> <1.0.1-1.fc40.copr8128148
> >1.0.3-1.fc40.copr8500754
> R-CRAN-openssl.x86_64
> <2.3.0-1.fc40.copr8401830
> >2.3.1-1.fc40.copr8497648
> R-CRAN-pillar.noarch
> <1.10.0-1.fc40.copr8405713
> >1.10.1-1.fc40.copr8483421
> R-CRAN-processx.x86_64
> <3.8.4-1.fc40.copr7353601
> >3.8.5-1.fc40.copr8491723
> R-CRAN-xfun.x86_64
> <0.49-1.fc40.copr8197470
> >0.50-1.fc40.copr8483452
> gdb.x86_64
> <15.2-3.fc40
> >15.2-4.fc40
> gdb-headless.x86_64
> <15.2-3.fc40
> >15.2-4.fc40
> gstreamer1.x86_64
> <1.24.10-1.fc40
> >1.24.11-1.fc40
> gstreamer1-plugins-base.x86_64
> <1.24.10-1.fc40
> >1.24.11-1.fc40
> hwdata.noarch
> <0.390-1.fc40
> >0.391-1.fc40
> js-jsroot.noarch
> <7.7.5-1.fc40
> >7.8.0-1.fc40
> libedit.x86_64
> <3.1-53.20240808cvs.fc40
> >3.1-54.20250104cvs.fc40
> libtirpc.x86_64
> <1.3.6-1.fc40
> >1.3.6-1.rc3.fc40
> libxcrypt.x86_64
> <4.4.37-1.fc40
> >4.4.37-4.fc40
> libxcrypt-devel.x86_64
> <4.4.37-1.fc40
> >4.4.37-4.fc40
> openjpeg2.x86_64
> <2.5.2-1.fc40
> >2.5.3-1.fc40
> openjpeg2-devel.x86_64
> <2.5.2-1.fc40
> >2.5.3-1.fc40
> openjpeg2-tools.x86_64
> <2.5.2-1.fc40
> >2.5.3-1.fc40
> python3-jupyroot.noarch
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> python3-root.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-cling.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-core.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-fonts.noarch
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-genvector.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-graf.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-graf-asimage.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-graf-gpad.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-graf-gpadv7.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-graf-postscript.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-graf-x11.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-graf3d.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-gui.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-gui-ged.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-hist.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-hist-painter.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-icons.noarch
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-io.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-io-xmlparser.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-mathcore.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-mathmore.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-matrix.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-minuit.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-minuit2.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-multiproc.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-net.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-physics.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-spectrum.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-tree.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-tree-dataframe.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-tree-ntuple.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-tree-player.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> root-vecops.x86_64
> <6.32.08-1.fc40
> >6.34.02-1.fc40
> systemd.x86_64
> <255.15-1.fc40
> >255.16-1.fc40
> systemd-libs.x86_64
> <255.15-1.fc40
> >255.16-1.fc40
> systemd-pam.x86_64
> <255.15-1.fc40
> >255.16-1.fc40
> tzdata.noarch
> <2024a-5.fc40
> >2024b-1.fc40
> tzdata-java.noarch
> <2024a-5.fc40
> >2024b-1.fc40
> vim-common.x86_64
> <2:9.1.919-1.fc40
> >2:9.1.1000-1.fc40
> vim-data.noarch
> <2:9.1.919-1.fc40
> >2:9.1.1000-1.fc40
> vim-enhanced.x86_64
> <2:9.1.919-1.fc40
> >2:9.1.1000-1.fc40
> vim-filesystem.noarch
> <2:9.1.919-1.fc40
> >2:9.1.1000-1.fc40
> vim-minimal.x86_64
> <2:9.1.919-1.fc40
> >2:9.1.1000-1.fc40
> xxd.x86_64
> <2:9.1.919-1.fc40
> >2:9.1.1000-1.fc40
> xxhash-libs.x86_64
> <0.8.2-4.fc40
> >0.8.3-1.fc40
> 
> ```

And these are the changes in package repositories as reported by `dnf --installed list` (should to my understanding not cause a difference as long as package versions didn’t change in the list above):

> **Changes in package repositories**
>
> ```auto
> alternatives.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> audit-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> authselect.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> authselect-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> basesystem.noarch
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> bash.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> bzip2.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> bzip2-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> ca-certificates.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> coreutils.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> coreutils-common.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> cracklib.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> crypto-policies.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> curl.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> cyrus-sasl-lib.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> dnf.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> dnf-data.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> elfutils-default-yama-scope.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> elfutils-libelf.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> elfutils-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> expat.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> fedora-gpg-keys.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> fedora-release-common.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> fedora-release-container.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> fedora-release-identity-container.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> fedora-repos.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> file-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> filesystem.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> findutils.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> gawk.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> gdbm.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> gdbm-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> glib2.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> glibc.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> glibc-common.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> glibc-minimal-langpack.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> gmp.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> gnupg2.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> gnutls.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> grep.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> gzip.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> ima-evm-utils.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> json-c.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> keyutils-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> krb5-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libacl.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libarchive.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libassuan.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libattr.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libb2.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libblkid.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libbrotli.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libcap.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libcap-ng.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libcom_err.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libcomps.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libcurl.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libdnf.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libeconf.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libevent.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libffi.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libfsverity.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libgcc.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libgcrypt.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libgomp.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libgpg-error.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libidn2.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libksba.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libmodulemd.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libmount.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libnghttp2.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libnsl2.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libpsl.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libpwquality.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> librepo.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libselinux.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libsemanage.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libsepol.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libsmartcols.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libsolv.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libssh.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libssh-config.noarch
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libstdc++.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libtasn1.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libtirpc.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libtool-ltdl.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libunistring.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libuuid.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libverto.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libxcrypt.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libxml2.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> libyaml.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> libzstd.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> lua-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> lz4-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> mpdecimal.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> mpfr.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> ncurses-base.noarch
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> ncurses-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> nettle.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> npth.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> openjpeg2.x86_64
> <@fedora
> >@updates
> openjpeg2-devel.x86_64
> <@fedora
> >@updates
> openjpeg2-tools.x86_64
> <@fedora
> >@updates
> openldap.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> openssl-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> p11-kit.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> p11-kit-trust.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> pam.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> pam-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> pcre2.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> pcre2-syntax.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> popt.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> publicsuffix-list-dafsa.noarch
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> python-pip-wheel.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> python3.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> python3-dnf.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> python3-hawkey.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> python3-libcomps.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> python3-libdnf.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> python3-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> python3-rpm.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> readline.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> rootfiles.noarch
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> rpm.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> rpm-build-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> rpm-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> rpm-sequoia.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> rpm-sign-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> sed.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> setup.noarch
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> shadow-utils.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> sqlite-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> sudo.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> systemd-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> tar.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> tpm2-tss.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> tzdata.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> util-linux-core.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> vim-data.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> vim-minimal.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> xz.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> xz-libs.x86_64
> <@b51e2e8493a94e2ab20c2a2c6df27bac
> >@cb7e6c571d914723a3cc571c21629501
> yum.noarch
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> zchunk-libs.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> zlib-ng-compat.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> zstd.x86_64
> <@e3ce1e6e183146e8981adbc063aec76f
> >@a587d8ccfeea4fb18a9762cb93e9a246
> 
> ```

---

<div class="post-metadata">

### Author: ![2xB](https://discourse.vtk.org/user_avatar/discourse.vtk.org/2xb/32/7543_2.png) [@2xB](https://discourse.vtk.org/u/2xB)
#### Post date: [January 17, 2025, 5:50pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/6 "2025-01-17T17:50:33Z")

</div>

After staring at this a bit thanks to writing the above post, I believe that CERN ROOT may include the nlohmann JSON package as well and CERN ROOT just got updated, so potentially ROOT and VTK are not getting along due to namespace conflicts.

---

<div class="post-metadata">

### Author: ![2xB](https://discourse.vtk.org/user_avatar/discourse.vtk.org/2xb/32/7543_2.png) [@2xB](https://discourse.vtk.org/u/2xB)
#### Post date: [January 17, 2025, 6:11pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/7 "2025-01-17T18:11:22Z")

</div>

I now also reported this to CERN ROOT: [ROOT & VTK JSON namespace conflicts · Issue #17451 · root-project/root · GitHub](https://github.com/root-project/root/issues/17451) That issue also mentions a way to test changes to VTK using the CI of our public project. If a minimal working example would be helpful, I could certainly also try to create that.

---

<div class="post-metadata">

### Author: ![2xB](https://discourse.vtk.org/user_avatar/discourse.vtk.org/2xb/32/7543_2.png) [@2xB](https://discourse.vtk.org/u/2xB)
#### Post date: [January 21, 2025, 4:17pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/8 "2025-01-21T16:17:35Z")

</div>

This is a pure VTK issue not related to CERN ROOT. I have created a minimal reproducer just using VTK: [GitHub - 2xB/vtkcmakeissue](https://github.com/2xB/vtkcmakeissue) That small repository has a pipeline that fails with the error I reported above, the full log for the last CI run can be found here: [Merge pull request #1 from 2xB/ci-reducedependencies · 2xB/vtkcmakeissue@4c7fe01 · GitHub](https://github.com/2xB/vtkcmakeissue/actions/runs/12890997348/job/35941904407)

I have no idea how it can be that this issue just started happening a few weeks ago without any obvious updates to related Fedora packages… If I should create an issue in the VTK issue tracker, please tell.

---

<div class="post-metadata">

### Author: ![jaswantp](https://discourse.vtk.org/user_avatar/discourse.vtk.org/jaswantp/32/10046_2.png) [@jaswantp](https://discourse.vtk.org/u/jaswantp)
#### Post date: [January 21, 2025, 4:22pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/9 "2025-01-21T16:22:21Z")

</div>

Yes, please create an issue in [https://gitlab.kitware.com/vtk/vtk/-/issues/new](https://gitlab.kitware.com/vtk/vtk/-/issues/new) and someone will investigate.

---

<div class="post-metadata">

### Author: ![2xB](https://discourse.vtk.org/user_avatar/discourse.vtk.org/2xb/32/7543_2.png) [@2xB](https://discourse.vtk.org/u/2xB)
#### Post date: [January 21, 2025, 6:21pm UTC](https://discourse.vtk.org/t/cmake-error-vtk-nlohmannjson/15170/10 "2025-01-21T18:21:22Z")

</div>

Okay, here you go: [https://gitlab.kitware.com/vtk/vtk/-/issues/19588](https://gitlab.kitware.com/vtk/vtk/-/issues/19588) The workaround for us for now is to add `find_package(nlohmann_json REQUIRED)` to our `CMakeLists.txt`…