Issues with conda installation of root 6.32 on MacOS

[abrac]

Hi all,

I recently tried updating ROOT on my MacOS machine (running on an apple M1 chip, and running version 14.3.1) from conda. After doing so, I bumped into this error trying to run it:
error:* *header ‘mdspan’ not found

header “mdspan”

^

input_line_1:1:10: note: submodule of top-level module ‘std’ implicitly imported here

#include

^

Warning in cling::IncrementalParser::CheckABICompatibility():

Failed to extract C++ standard library version.

Warning in cling::IncrementalParser::CheckABICompatibility():

Possible C++ standard library mismatch, compiled with _LIBCPP_ABI_VERSION ‘1’

Extraction of runtime standard library version was: ‘’

Replaced symbol at_quick_exit cannot be found in JIT!

---

When trying to run pyROOT, these errors became more extensive. In trying to solve this problem I came across this thread:

Root got error with anaconda

Hi expert, I use conda to install root and succeed. however when I type root, it report the following message /opt/anaconda3/envs/hep/etc/cling/std_darwin.modulemap:153:10: error: header ‘mdspan’ not found header “mdspan” ^ input_line_1:1:10: note: submodule of top-level module ‘std’ implicitly imported here #include ^ Warning in cling::IncrementalParser::CheckABICompatibility(): Failed to extract C++ standard library version. Warning in cling::IncrementalParser::CheckABICompatibilit…

It seems that the solution is to use my older version of root (6.30.4) instead of updating to 6.32. That’s not a big deal for me, since I have a separate linux machine where 6.32 should work. However, I thought it was important to post about it since it seems to be an issue with the latest root version on MacOS and I was wondering if there would be any update or patch for this soon/if a solution has already been found.

Thanks!

[Danilo]

Hi,

Thanks for the post. While we reply to this, the holiday period is starting and more and more colleagues are not at work any more, I can maybe propose a workaround for macOS.
Brew seems to be a very efficient vector to distribute ROOT for macOS: is that an option for you? Otherwise binaries for releases are distributed or we could look at building from sources (it’s literally a matter of 3 commands…).

D

[abrac]

Hi,

Thanks for your response! I figured it would take a while for a solution to come through if it was something wrong with the conda install for 6.32, especially with the holidays coming up. Brew is an option for me, I have no problem using it. Just wanted to put the information out there in case others encounter the same problem and so that folks know there’s an issue with the conda method!

Cheers,
Aitor

[Danilo]

Hi Aitor,

Thanks, you did well reporting the matter here!

Cheers,
D

[Heidi_M_Schellman]

Hello, I have also run into this issue. I anticipated issues so have a backup machine to run on.

I updated to MacOS 15.2 on intel hardware, upgraded to Xcode 16.2

Installed Root 6.32.00 from conda. I have been able to compile and build my code but on execution

root
/Users/schellma/miniconda/envs/new/etc/cling/std_darwin.modulemap:153:10: error: header ‘mdspan’ not found
header “mdspan”
^
input_line_1:1:10: note: submodule of top-level module ‘std’ implicitly imported here
#include
^
Warning in cling::IncrementalParser::CheckABICompatibility():
Failed to extract C++ standard library version.
Warning in cling::IncrementalParser::CheckABICompatibility():
Possible C++ standard library mismatch, compiled with _LIBCPP_ABI_VERSION ‘1’
Extraction of runtime standard library version was: ‘’

| Welcome to ROOT 6.32.00
| (c) 1995-2024, The ROOT Team; conception: R. Brun, F. Rademakers |
| Built for macosx64 on Jun 21 2024, 15:10:47 |
| From heads/v6-32-patches@tags/v6-32-00 |
| With |

Try ‘.help’/‘.?’, ‘.demo’, ‘.license’, ‘.credits’, ‘.quit’/‘.q’

LLVM ERROR: out of memory
Allocation failed

[Danilo]

Hi Heidi,

thanks for the report.
You can have ROOT on your mac either with brew or compiling from sources.
For example:

git clone --depth 1 --branch v6-32-08 https://github.com/root-project/root
mkdir build && cd build
cmake ../root
make -j 8
source bin/thisroot.sh

On intel hardware, based on statistics accumulated on our infrastructure, I estimate a build time of 30 minutes.

Cheers,
D

[Heidi_M_Schellman]

Ok, I got this to work after substantial pain. The main thing is that conda has a bad habit of installing new versions of python - which are then not compatible with your root version.

Suggest that people, taking this path and using conda, install everything they could possibly think of except root in a new conda environment - and then build root to match that environment.