Failed to Open ROOT after today's update

ROOT
1

_On my end, after today’s sequoia 15.4 update. Homebrew failed to correctly build root (I tried to reinstall but no luck either.) I suspect it is a change of library or some C++ patches in the new MAC OS system. Also please see the following command line when I tried to open root after the installation:

/opt/homebrew/Cellar/root/6.34.06/etc/root/cling/std_darwin.modulemap:540:12: error: header ‘experimental/__memory’ not found
header “experimental/__memory”
^
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: ‘’
input_line_2:1:2: fatal error: module file '/tmp/root-20250327-18543-ll7y48/root-6.34.06/builddir/lib/mach_port_t.pcm’ not found: module file not found
#include <cling/Interpreter/RuntimeUniverse.h>
^
input_line_2:1:2: note: imported by module ‘pthread’ in ‘/opt/homebrew/Cellar/root/6.34.06/lib/root/pthread.pcm’
input_line_2:1:2: note: imported by module ‘std’ in ‘/opt/homebrew/Cellar/root/6.34.06/lib/root/std.pcm’
input_line_2:1:2: note: imported by module ‘Cling_Runtime_Extra’ in ‘/opt/homebrew/Cellar/root/6.34.06/lib/root/Cling_Runtime_Extra.pcm’
input_line_2:1:2: note: imported by module ‘Cling_Runtime’ in ‘/opt/homebrew/Cellar/root/6.34.06/lib/root/Cling_Runtime.pcm’
<<< cling interactive line includer >>>: fatal error: module file ‘/opt/homebrew/Cellar/root/6.34.06/lib/root/std.pcm’ is out of date and needs to be rebuilt
<<< cling interactive line includer >>>: note: imported by module ‘Darwin’ in ‘/opt/homebrew/Cellar/root/6.34.06/lib/root/Darwin.pcm’
Failed to load module Darwin

ROOT Version: 6.34.06
Platform: MacOS sequoia 15.4
Compiler: homebrew (xcode 16.3)

2

Hi @yansonhuang,

Welcome to the ROOT forum and thanks for your question.

Can you please share the build configuration that you are using so that I can try and reproduce the issue on my end?

Cheers,
Devajith

3

Hello @devajith,
Thanks for your reply. I use a Macbook and the build is Homebrew: i.e.
brew install root
root
Then this error message showed up.

4

Ahh, I see. I suspect it’s caused by root not being installed properly after the upgrade.

Can you try completely uninstalling root and installing again?

If that doesn’t work, you can download pre-compiled binaries from Installing ROOT - ROOT rather than via Homebrew

EDIT:

We do not have a release version for sequoia 15.4 yet. You can build root from source instead

Cheers,
Devajith

5

Hello, again, I have tried to uninstall homebrew and install again but no luck either. I have issued a troubleshooting message to homebrew. Hopefully, it will get resolved shortly.

I will also try to build root from the source later today as you suggested. I will return here if I still have issues.

6

Thanks. In the meantime we are closely looking at the issue to understand if an action on our side is required.

7

Being a chronic upgrader, I have seen this sequence of events many times before:

  1. New version of ROOT comes to Homebrew, everything works beautifully
  2. New version of MacOS and Xcode comes out, root doesn’t work any more
  3. ROOT formula adapts to Xcode, everything works beautifully again

Looking at my notes, it usually has something to do with the version of the C++ standard library, and sometimes I can find workarounds, but generally I have found it easier to wait for the experts to fix it, and I thank them for their efforts in maintaining Homebrew ROOT.

8

Hi @yansonhuang, @devajith ,
I am running into the same problem. I tried to install it from source as well but no luck. Is there any update? Have you manage to fix it or install it from source?

9

We are aware of the issue and trying to fix this on our side.