# Latest **URL:** https://alice-talk.web.cern.ch/latest.md [Latest](https://alice-talk.web.cern.ch/latest.md) · [Categories](https://alice-talk.web.cern.ch/categories.md) · [Tags](https://alice-talk.web.cern.ch/tags.md) --- ## [Terminology confusion. What is "Muon spectrometer"?](https://alice-talk.web.cern.ch/t/terminology-confusion-what-is-muon-spectrometer/1686)
**Author:** [@kmkm](https://alice-talk.web.cern.ch/u/kmkm)\ **Replies:** 0\ **Last updated:** [November 10, 2026, 11:48am UTC](https://alice-talk.web.cern.ch/t/terminology-confusion-what-is-muon-spectrometer/1686 "2026-11-10T11:48:51Z")
Hello, I’d like to know what “Muon spectrometer” refers to. Sources don’t seem to be in agreement on that. On the official website, MFT (muon forward tracker) and Muon Spectrometer are listed as separate entities: H… --- ## [Issue while building O2Physics on macOS during compiling ROOT@v6-32-06-alice10](https://alice-talk.web.cern.ch/t/issue-while-building-o2physics-on-macos-during-compiling-root-v6-32-06-alice10/1678)
**Author:** [@atabikh](https://alice-talk.web.cern.ch/u/atabikh)\ **Replies:** 1\ **Last updated:** [May 14, 2026, 1:47pm UTC](https://alice-talk.web.cern.ch/t/issue-while-building-o2physics-on-macos-during-compiling-root-v6-32-06-alice10/1678 "2026-05-14T13:47:44Z")
Hello, I followed the step-by-step instructions for installing O2Physics on my Mac (macOS Tahoe 26.0.1) as described in the official O2 documentation. However, the build consistently crashes during the compilation of RO… --- ## [TGrid::Connect not working](https://alice-talk.web.cern.ch/t/tgrid-connect-not-working/1683)
**Author:** [@dstocco](https://alice-talk.web.cern.ch/u/dstocco)\ **Replies:** 2\ **Last updated:** [February 24, 2026, 8:30am UTC](https://alice-talk.web.cern.ch/t/tgrid-connect-not-working/1683 "2026-02-24T08:30:26Z")
Dear all, I have an issue with TGrid::Connect that prevents me to run any O2 workflow. If I do: root -l TGrid::Connect("alien://") Info in \: Opening connection to JCentral. Please wait Info i… --- ## [Ubuntu 24.04 binaries availability](https://alice-talk.web.cern.ch/t/ubuntu-24-04-binaries-availability/1684)
**Author:** [@kmkm](https://alice-talk.web.cern.ch/u/kmkm)\ **Replies:** 0\ **Last updated:** [February 23, 2026, 4:23pm UTC](https://alice-talk.web.cern.ch/t/ubuntu-24-04-binaries-availability/1684 "2026-02-23T16:23:46Z")
O2Physics updates take a really long time even if performed in relatively small time intervals, like a week. What I’m doing is, as per documentation, a ‘git pull‘ in alidist, O2 and O2Physics directories and then go on t… --- ## [O2 installation failed on ROOT](https://alice-talk.web.cern.ch/t/o2-installation-failed-on-root/1682)
**Author:** [@nnovitzk](https://alice-talk.web.cern.ch/u/nnovitzk)\ **Replies:** 1\ **Last updated:** [February 9, 2026, 4:40pm UTC](https://alice-talk.web.cern.ch/t/o2-installation-failed-on-root/1682 "2026-02-09T16:40:33Z")
I have an issue installing O2, failed on the ROOT installation every time. I have uninstalled the root ( which root root not found), here is the log: --- ## [Problem compiling O2 on Ubuntu 24.04 - ONNXRuntime](https://alice-talk.web.cern.ch/t/problem-compiling-o2-on-ubuntu-24-04-onnxruntime/1681)
**Author:** [@pcortese](https://alice-talk.web.cern.ch/u/pcortese)\ **Replies:** 0\ **Last updated:** [December 5, 2025, 2:37pm UTC](https://alice-talk.web.cern.ch/t/problem-compiling-o2-on-ubuntu-24-04-onnxruntime/1681 "2025-12-05T14:37:32Z")
Hello, I’m facing a weird problem when compiling O2 on Ubuntu 24.04. It looks like one of the packages to be downloaded named “eigen-populate” always fails to download. Do you have any suggestion? The log is attached h… --- ## [O2Physics - Error while executing track\_env](https://alice-talk.web.cern.ch/t/o2physics-error-while-executing-track-env/1680)
**Author:** [@wpieroza](https://alice-talk.web.cern.ch/u/wpieroza)\ **Replies:** 0\ **Last updated:** [November 28, 2025, 10:42am UTC](https://alice-talk.web.cern.ch/t/o2physics-error-while-executing-track-env/1680 "2025-11-28T10:42:39Z")
Hi, I have an issue with the alibuild init command for O2Physics. It works as usual when I call it for every other module, but when I call it for O2Physics, this error pops up: DEBUG: User has analytics id. Pushing ana… --- ## [O2 installation via CVMFS on AlmaLinux 9.4](https://alice-talk.web.cern.ch/t/o2-installation-via-cvmfs-on-almalinux-9-4/1679)
**Author:** [@eborisov](https://alice-talk.web.cern.ch/u/eborisov)\ **Replies:** 0\ **Last updated:** [October 15, 2025, 12:16pm UTC](https://alice-talk.web.cern.ch/t/o2-installation-via-cvmfs-on-almalinux-9-4/1679 "2025-10-15T12:16:48Z")
Dear O2 developers, I’m trying to use the ready-to-run O2 installation via CVMFS, as described in the quickstart guide. However, when I run the command /cvmfs/alice-nightlies.cern.ch/bin/alienv I get the following e… --- ## [O2 HTCondor multi-node job](https://alice-talk.web.cern.ch/t/o2-htcondor-multi-node-job/1676)
**Author:** [@wpieroza](https://alice-talk.web.cern.ch/u/wpieroza)\ **Replies:** 0\ **Last updated:** [September 23, 2025, 12:18pm UTC](https://alice-talk.web.cern.ch/t/o2-htcondor-multi-node-job/1676 "2025-09-23T12:18:15Z")
Hi, I set up HTCondor cluster for team to run O2 jobs and I want to test how it performs. I run o2-sim in parallel universe and I noticed that instead of one simulation executed on two nodes, two simulations executed on… --- ## [GPU-vulkan-errors in 20.04 LTS](https://alice-talk.web.cern.ch/t/gpu-vulkan-errors-in-20-04-lts/1661)
**Author:** [@das](https://alice-talk.web.cern.ch/u/das)\ **Replies:** 4\ **Last updated:** [July 4, 2025, 10:46am UTC](https://alice-talk.web.cern.ch/t/gpu-vulkan-errors-in-20-04-lts/1661 "2025-07-04T10:46:18Z")
Dear Experts, facing this error in new O2 building in ubuntu 20.04 LTS: 2025-04-07@08:40:00:DEBUG:O2:O2:0: FAILED: GPU/GPUTracking/display/CMakeFiles/O2lib-GPUTrackingDisplay.dir/backend/GPUDisplayBackendVulkan.cxx.o … --- ## [O2Physics build error cmake](https://alice-talk.web.cern.ch/t/o2physics-build-error-cmake/1668)
**Author:** [@clotteau](https://alice-talk.web.cern.ch/u/clotteau)\ **Replies:** 2\ **Last updated:** [May 28, 2025, 4:33pm UTC](https://alice-talk.web.cern.ch/t/o2physics-build-error-cmake/1668 "2025-05-28T16:33:04Z")
Hello, I wanted to update O2Physics (on my master branch) with git reset --hard git pull --rebase And alidist with git pull --rebase upstream master And when I try to build O2Physics with the command aliBuild build … --- ## [Issue with Missing AliAnalysisTaskSE.h When Running Local ALICE Analysis](https://alice-talk.web.cern.ch/t/issue-with-missing-alianalysistaskse-h-when-running-local-alice-analysis/1656)
**Author:** [@bonen](https://alice-talk.web.cern.ch/u/bonen)\ **Replies:** 2\ **Last updated:** [April 7, 2025, 10:41am UTC](https://alice-talk.web.cern.ch/t/issue-with-missing-alianalysistaskse-h-when-running-local-alice-analysis/1656 "2025-04-07T10:41:32Z")
Hello everyone, I’ve been working on setting up a local analysis using O2Physics on my computer. I have spent quite some time modifying my analysis script to process my own dataset following the steps outlined in the AL… --- ## [Jet Identification and Discriminator Parameters: Comparison Between ALICE and CMS](https://alice-talk.web.cern.ch/t/jet-identification-and-discriminator-parameters-comparison-between-alice-and-cms/1662)
**Author:** [@bonen](https://alice-talk.web.cern.ch/u/bonen)\ **Replies:** 0\ **Last updated:** [April 7, 2025, 10:37am UTC](https://alice-talk.web.cern.ch/t/jet-identification-and-discriminator-parameters-comparison-between-alice-and-cms/1662 "2025-04-07T10:37:15Z")
Hi everyone, In CMS analyses, jet identification often involves applying a set of cut-based criteria and using specific jet discriminator parameters, especially for tasks like quark/gluon discrimination. These parameter… --- ## [Errors with ubuntu 20.04 LTS](https://alice-talk.web.cern.ch/t/errors-with-ubuntu-20-04-lts/1491)
**Author:** [@das](https://alice-talk.web.cern.ch/u/das)\ **Replies:** 4\ **Last updated:** [April 6, 2025, 8:53am UTC](https://alice-talk.web.cern.ch/t/errors-with-ubuntu-20-04-lts/1491 "2025-04-06T08:53:04Z")
dear @all if anyone using ubuntu 20.04 and facing errors like this : aliBuild init O2Physics@master WARNING: using existing recipes from ./alidist ERROR: Specified default \`release’ is not compatible with the packages … --- ## [Bethe-Bloch Curve](https://alice-talk.web.cern.ch/t/bethe-bloch-curve/1659)
**Author:** [@amanojna](https://alice-talk.web.cern.ch/u/amanojna)\ **Replies:** 2\ **Last updated:** [April 5, 2025, 5:57pm UTC](https://alice-talk.web.cern.ch/t/bethe-bloch-curve/1659 "2025-04-05T17:57:14Z")
Dear Experts, I wanted to plot the theoretically calculated Bethe-Bloch curve (dE/dx vs p) for the ALICE TPC for different particles (e-, pions, muons, kaons etc). I could not find any documentations for it. Could you k… --- ## [Grid certificate problem on MacOS Sonoma after O2 rebuild](https://alice-talk.web.cern.ch/t/grid-certificate-problem-on-macos-sonoma-after-o2-rebuild/1609)
**Author:** [@kiversen](https://alice-talk.web.cern.ch/u/kiversen)\ **Replies:** 2\ **Last updated:** [September 5, 2024, 12:21pm UTC](https://alice-talk.web.cern.ch/t/grid-certificate-problem-on-macos-sonoma-after-o2-rebuild/1609 "2024-09-05T12:21:07Z")
Dear experts, This morning I have recompiled O2, and am now having issues with my grid certificate. Specifically, alien-token-init fails with the message: Could NOT establish connection (TCP socket) to alice-jcentral.… --- ## [New to the Group: O2 and O2 Physics Installed, But Missing AliRoot – How to Run Tasks in O2?](https://alice-talk.web.cern.ch/t/new-to-the-group-o2-and-o2-physics-installed-but-missing-aliroot-how-to-run-tasks-in-o2/1653)
**Author:** [@bonen](https://alice-talk.web.cern.ch/u/bonen)\ **Replies:** 0\ **Last updated:** [March 3, 2025, 11:00am UTC](https://alice-talk.web.cern.ch/t/new-to-the-group-o2-and-o2-physics-installed-but-missing-aliroot-how-to-run-tasks-in-o2/1653 "2025-03-03T11:00:16Z")
Hello everyone, I’m new to the group and I’ve successfully installed O2 and O2 Physics. However, I noticed that AliRoot doesn’t seem to be among the loaded modules. Does this mean that AliRoot or Aliphysics is not used … --- ## [AliRoot Module Loading Error](https://alice-talk.web.cern.ch/t/aliroot-module-loading-error/1652)
**Author:** [@bonen](https://alice-talk.web.cern.ch/u/bonen)\ **Replies:** 0\ **Last updated:** [February 28, 2025, 8:02am UTC](https://alice-talk.web.cern.ch/t/aliroot-module-loading-error/1652 "2025-02-28T08:02:06Z")
I am encountering the following error while trying to use AliRoot on my lxplus account: Toolchain(52): ERROR: 105: Unable to locate a modulefile for ‘Toolchain/GCC-v4.9.3’ This error occurs when I try to enter AliRoot … --- ## [A question for O2Physics](https://alice-talk.web.cern.ch/t/a-question-for-o2physics/1651)
**Author:** [@yosu](https://alice-talk.web.cern.ch/u/yosu)\ **Replies:** 0\ **Last updated:** [February 23, 2025, 4:30am UTC](https://alice-talk.web.cern.ch/t/a-question-for-o2physics/1651 "2025-02-23T04:30:35Z")
log.txt (35.1 KB) 77%\] Building CXX object CMakeFiles/testRegexMatch.dir/test/testRegexMatch.cxx.o In file included from /Users/suyoupeng/alice/sw/SOURCES/Monitoring/v3.19.2/v3.19.2/examples/15-ODC.cxx:8: In file incl… --- ## [TPCQCVis package instalation in O2 environment](https://alice-talk.web.cern.ch/t/tpcqcvis-package-instalation-in-o2-environment/1649)
**Author:** [@creckzie](https://alice-talk.web.cern.ch/u/creckzie)\ **Replies:** 1\ **Last updated:** [February 7, 2025, 7:55am UTC](https://alice-talk.web.cern.ch/t/tpcqcvis-package-instalation-in-o2-environment/1649 "2025-02-07T07:55:47Z")
Dear experts, in order to perform QC work with the TPC, the TPCQCVis (TPCQCVis repository and instructions package is used. I have been using it for some time, until I had to reset my computer and install everything fr… --- ## [Issue with O2 installation](https://alice-talk.web.cern.ch/t/issue-with-o2-installation/1646)
**Author:** [@lgyulai](https://alice-talk.web.cern.ch/u/lgyulai)\ **Replies:** 0\ **Last updated:** [February 5, 2025, 3:34pm UTC](https://alice-talk.web.cern.ch/t/issue-with-o2-installation/1646 "2025-02-05T15:34:51Z")
Dear experts, My build fails during the compilation of KFParticle (but also similar errors and logs are produced for vgm and VMC) with the following errors: 2025-02-05@13:58:00:ERROR:O2Physics:KFParticle:0: Error while… --- ## [O2 DPG / EVTGEN](https://alice-talk.web.cern.ch/t/o2-dpg-evtgen/1202)
**Author:** [@sacharya](https://alice-talk.web.cern.ch/u/sacharya)\ **Replies:** 3\ **Last updated:** [January 24, 2025, 10:48pm UTC](https://alice-talk.web.cern.ch/t/o2-dpg-evtgen/1202 "2025-01-24T22:48:54Z")
I am trying to install O2 DPG packages in my local machine ( Mcbook Pro, macOS Monterey 12.3.1, Apple M1 pro). While trying to install EVTGEN, I face an error at Building PHOTOS@v.3.64 : aliBuild build EVTGEN --default… --- ## [Install O2Physics on Alma 9 on WSL issues](https://alice-talk.web.cern.ch/t/install-o2physics-on-alma-9-on-wsl-issues/1624)
**Author:** [@bbinjami](https://alice-talk.web.cern.ch/u/bbinjami)\ **Replies:** 1\ **Last updated:** [December 17, 2024, 8:39am UTC](https://alice-talk.web.cern.ch/t/install-o2physics-on-alma-9-on-wsl-issues/1624 "2024-12-17T08:39:08Z")
Good Day I get this output error when trying to install O2 physics: ==\> Unpacking FairRoot@v18.4.9-alice3: done ==\> Compiling O2@daily-20241011-0200 (use --debug for full output): done ==\> Compiling O2Physics@master (u… --- ## [Alienv not working](https://alice-talk.web.cern.ch/t/alienv-not-working/708)
**Author:** [@dkrupova](https://alice-talk.web.cern.ch/u/dkrupova)\ **Replies:** 10\ **Last updated:** [December 10, 2024, 11:50pm UTC](https://alice-talk.web.cern.ch/t/alienv-not-working/708 "2024-12-10T23:50:09Z")
Hi everyone, I am trying to use O2 software on MacOS Catalina 10.15.6 and I have several builds installed. All worked for me before, but now when I tried to use command ‘alienv enter O2/latest-dev-o2’ (or any other tag)… --- ## [Error with \`alienv enter\` in lxplus](https://alice-talk.web.cern.ch/t/error-with-alienv-enter-in-lxplus/1636)
**Author:** [@lecriste](https://alice-talk.web.cern.ch/u/lecriste)\ **Replies:** 1\ **Last updated:** [December 9, 2024, 3:17pm UTC](https://alice-talk.web.cern.ch/t/error-with-alienv-enter-in-lxplus/1636 "2024-12-09T15:17:54Z")
Hello, I am trying to enter the O2 environment on lxplus and get: $ /cvmfs/alice-nightlies.cern.ch/bin/alienv enter O2::nightly-20171130-1 ERROR: Unable to locate a modulefile for 'O2/nightly-20171130-1' It occurs in … --- ## [This error occurs to me very often can any body help me in that](https://alice-talk.web.cern.ch/t/this-error-occurs-to-me-very-often-can-any-body-help-me-in-that/1633)
**Author:** [@jtanwar](https://alice-talk.web.cern.ch/u/jtanwar)\ **Replies:** 0\ **Last updated:** [December 7, 2024, 6:09am UTC](https://alice-talk.web.cern.ch/t/this-error-occurs-to-me-very-often-can-any-body-help-me-in-that/1633 "2024-12-07T06:09:34Z")
SEVERE: Device derived-basic-consumer (43892) had at least one message above severity 5: Unhandled o2::framework::runtime\_error reached the top of main of o2-analysistutorial-derived-basic-consumer, device shutting down.… --- ## [Building ACTS with aliBuild fails](https://alice-talk.web.cern.ch/t/building-acts-with-alibuild-fails/1631)
**Author:** [@Cas](https://alice-talk.web.cern.ch/u/Cas)\ **Replies:** 0\ **Last updated:** [November 14, 2024, 9:22am UTC](https://alice-talk.web.cern.ch/t/building-acts-with-alibuild-fails/1631 "2024-11-14T09:22:17Z")
Dear all, To build ACTS I use the command aliBuild build ACTS -j 24 You can find the .sh file to build ACTS here alidist/acts.sh at master · alisw/alidist · GitHub However, this does not work. I get the following err… --- ## [Error while setting up workflow in o2-analysis-event-selection: Ill-formed URI](https://alice-talk.web.cern.ch/t/error-while-setting-up-workflow-in-o2-analysis-event-selection-ill-formed-uri/1629)
**Author:** [@gfomenko](https://alice-talk.web.cern.ch/u/gfomenko)\ **Replies:** 0\ **Last updated:** [November 10, 2024, 2:48pm UTC](https://alice-talk.web.cern.ch/t/error-while-setting-up-workflow-in-o2-analysis-event-selection-ill-formed-uri/1629 "2024-11-10T14:48:37Z")
Dear all, Im trying to analise my AO2D file. While using command: o2-analysis-event-selection --aod-file=file://AO2D.root --configuration=config.json | o2-analysis-timestamp --configuration json://config.json --aod-f… --- ## [Issue with Python-modules-list while building O2 using aliBuild](https://alice-talk.web.cern.ch/t/issue-with-python-modules-list-while-building-o2-using-alibuild/1625)
**Author:** [@pfetterd](https://alice-talk.web.cern.ch/u/pfetterd)\ **Replies:** 1\ **Last updated:** [October 18, 2024, 1:01pm UTC](https://alice-talk.web.cern.ch/t/issue-with-python-modules-list-while-building-o2-using-alibuild/1625 "2024-10-18T13:01:47Z")
Hi everyone, I’m encountering an issue while trying to build O2 with aliBuild. The build fails when it reaches the Python-modules-list@1.0. Here’s the error I keep getting: ==\> Building Python-modules-list@1.0 ==\> Pyt… --- ## [Installing O2Physics in LXPLUS-Alma9](https://alice-talk.web.cern.ch/t/installing-o2physics-in-lxplus-alma9/1623)
**Author:** [@amanojna](https://alice-talk.web.cern.ch/u/amanojna)\ **Replies:** 2\ **Last updated:** [October 10, 2024, 5:38am UTC](https://alice-talk.web.cern.ch/t/installing-o2physics-in-lxplus-alma9/1623 "2024-10-10T05:38:46Z")
Hello Experts, Any one know how to install the O2Physics in CERNBOX via LXPLUS? When i try to install it by creating a folder alice in /eos/user/, im getting the following error: ==\> You have packages in development mo… [Next page](https://alice-talk.web.cern.ch/latest.md?page=1)