Starting build on ROOT-debian10-i386/soversion, ROOT-performance-centos8-multicore/cxx17, ROOT-ubuntu18.04/nortcxxmod, ROOT-ubuntu2004/python3, mac1015/cxx17, mac11/cxx14, windows10/cxx14
How to customize builds

Build failed on ROOT-ubuntu18.04/nortcxxmod.
Running on sft-ubuntu-1804-2.cern.ch:/build/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.test.test_stresshistogram_interpreted

Build failed on ROOT-performance-centos8-multicore/cxx17.
Running on olbdw-01.cern.ch:/data/sftnight/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.test.test_stresshistogram
• projectroot.test.test_stresshistogram_interpreted

Build failed on ROOT-debian10-i386/soversion.
Running on pcepsft10.dyndns.cern.ch:/build/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.test.test_stresshistogram_interpreted

Build failed on windows10/cxx14.
Running on null:C:\build\workspace\root-pullrequests-build
See console output.

Failing tests:

• projectroot.test.test_stresshistogram_interpreted

Build failed on ROOT-ubuntu2004/python3.
Running on root-ubuntu-2004-1.cern.ch:/home/sftnight/build/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.roottest.python.distrdf.dask.roottest_python_distrdf_dask_test_all
• projectroot.roottest.python.distrdf.spark.roottest_python_distrdf_spark_test_all
• projectroot.test.test_stresshistogram_interpreted

Build failed on mac11/cxx14.
Running on macphsft23.dyndns.cern.ch:/Users/sftnight/build/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.test.test_stresshistogram
• projectroot.roottest.python.distrdf.common.roottest_python_distrdf_common_test_all
• projectroot.roottest.python.distrdf.dask.roottest_python_distrdf_dask_test_all
• projectroot.roottest.python.distrdf.spark.roottest_python_distrdf_spark_test_all
• projectroot.test.test_stresshistogram_interpreted

Build failed on mac1015/cxx17.
Running on macitois22.dyndns.cern.ch:/Users/sftnight/build/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.roottest.python.distrdf.dask.roottest_python_distrdf_dask_test_all
• projectroot.roottest.python.distrdf.spark.roottest_python_distrdf_spark_test_all
• projectroot.test.test_stresshistogram_interpreted

Applying the patch causes a crash when cloning a THnD. Here is a simple code reproducing this:

int bins[] = {10}; double xmin[] = {0}; double xmax[] = {10}; 
auto h = new THnD("h","h",1,bins,xmin,xmax);
h->Sumw2();
h->Clone();

@pcanal , any idea what could be the problem ?

I think in the I/O rule define in the Linkdef.h should be version and not versions, otherwise the rule is applied to all versions, including the current one.
The next patch should fix this

Starting build on ROOT-debian10-i386/soversion, ROOT-performance-centos8-multicore/cxx17, ROOT-ubuntu18.04/nortcxxmod, ROOT-ubuntu2004/python3, mac1015/cxx17, mac11/cxx14, windows10/cxx14
How to customize builds