Issues with TFileMerger in v5-33-02a

Dear Root experts,

My macros which used TFileMerger utility, and which worked perfectly fine in Root v5-30-06, stopped working after I have upgraded to v5-33-02a. Was there any recent addition in TFileMerger which is not backward compatible?

Now when I call Merge() I have a crash, and upon exiting Root session I have the following message:

Root > Function mergeOutput() busy flag cleared

root [1] .q
Fatal in <TFileMerger::RecursiveRemove>: Output file of the TFile Merger (targetting mergedOutputCentrality.root) has been deleted (likely due to a TTree larger than 100Gb)

However, looking at the size of this file:

-rw-r--r-- 1 anteb alice 1.5M Apr 16 18:23 mergedOutputCentrality.root

So the file is perfectly fine. If I just simply switch to Root v5-30-06 and use the very same merging macro, over the very same files, the merging works perfectly fine.

Is somebody else also experiencing problems with TFileMerger in more recent Root versions?


Hi Ante,

What is the strack trace of the crash? Most likely it is related to which got fixed today in the trunk (revision 43764).


Hi Phillipe,

I have attached the stack trace now.

merging.txt (9.35 KB)


This was reported as and is apriori fixed in the trunk.