问题
Here's a rather advanced question for true ClearCase experts:
I frequently perform a rebase on a ClearCase snapshot view that has just a very limited number of small changes in few files (e.g. file1.c, file2.c, file3.c).
I do it with the following on the UNIX command line:
cleartool rebase -recommended -complete
Sometimes, while this command runs, out of the blue, and for no exlained reasons (yet), I get prompted for manual input to solve some "merge" conflicts. But they make no sense to me, as they happen in file(s) that I NEVER EVER TOUCHED -- and which ONLY ONE OTHER DEVELOPER EVER TOUCHES.
The "merge" prompts I see when this scenario happens during a rebase look usually like:
"Do you want INSERTION from file x? [yes/no]"
or
"Do you want DELETION from file y? [yes/no]"
or
"Do you want CHANGES from file z? [yes/no]".
Etc.
I have no clue why these "conflicts" are happening. Additionally, it's really hard (see impossible) to make good decisions because the details are shown with a very narrow number of columns, and there's hardly any way to guess right. Using graphical merging is not an option here because this is meant for an automation script that should ideally never ask for user input.
What I do know about this scenario is:
We have a team of 6 developers. 5 of us usually work the same limited number of files... say file1.c, file2.c, file.3.c
I work on a child development stream on these three files. And when I'm done, I normally deliver up to the default parent stream.
On the occasions where the "merge conflicts" on rebase happened, it's always on a totally DIFFERENT FILE -- one that is ONLY EVER TOUCHED by JUST ONE other developer in the team (it's a module that HE owns, NO ONE EVER TOUCHES THAT FILE BUT HIM). Let's call him developer #6.
When this strange "merge conflict" on rebase happens, I've usually been working for an extended time in my own development child stream (always with a snapshot view), and I've done a couple rebases (at least 3) to bring other changes ALL made by other developers (in file1.c, file2.c and file3.c) and which I needed to complete my work.
But, the other developer (#6), the ONLY ONE working on banana.c, had made changes to that file, in at least two of the three rebases activities that were created in the snapshot view of my child development stream.
Again, I repeat, I NEVER touched banana.c, and none of the 5 other developers ever did, except for the guy (#6) who owns the banana.c module.
And there, it happened - ClearCase asked me for manual input to solve a "merge" conflict with banana.c when doing "cleartool rebase -recommended -complete".
How can this be possible???
How can a file require "merging" when doing rebase if there is ONLY EVER one single developer making changes to it?
It's as if ClearCase got confused between different versions of banana.c in at least two of the three rebase activities automatically created in my stream (which both modified banana.c) and prompted me for "merge conflict" resolution (even though I never ever touched banana.c and only one developer (#6) ever did modify that file).
. . .
UPDATE: AUGUST 31ST 2015
Here's a log from an occurrence of the problem on August 28th 2015
Needs Merge "/view/MYDYNAMICVIEW/vobs/DIRLEVEL1/DIRLEVEL2/SOMEFILE.cpp" to /main/MAIN_INT_STREAM/SUB_STREAM/CHECKEDOUT from /main/MAIN_INT_STREAM/SUB_STREAM/MY_DEV_STREAM/37 base /main/
MAIN_INT_STREAM/SUB_STREAM/150
********************************
<<< file 1: /view/MYDYNAMICVIEW/vobs/DIRLEVEL1/DIRLEVEL2/SOMEFILE.cpp@@/main/MYDYNAMICVIEW/SUB_STREAM/150
>>> file 2: /view/MYDYNAMICVIEW/vobs/DIRLEVEL1/DIRLEVEL2/SOMEFILE.cpp@@/main/MYDYNAMICVIEW/SUB_STREAM/MY_DEV_STREAM/37
>>> file 3: /view/MYDYNAMICVIEW/vobs/DIRLEVEL1/DIRLEVEL2/SOMEFILE.cpp
********************************
...CUT FOR BREVITY...
*** Automatic: Applying DELETION from file 3 [deleting base line 123]
...CUT FOR BREVITY...
*** Automatic: Applying INSERT from file 3 [lines 123-124]
...CUT FOR BREVITY...
*** Automatic: Applying CHANGE from file 3 [lines 1329-1335]
...CUT FOR BREVITY...
*** No Automatic Decision Possible
merge: Warning: *** Aborting...
Missing charsets in String to FontSet conversion
Missing charsets in String to FontSet conversion
Missing charsets in String to FontSet conversion
Cannot convert string "-misc-kochi mincho-medium-r-normal--0-*-*-*-*-*-*-*" to type FontSet
...GMERGE POPPED HERE...
Moved contributor "/view/MYDYNAMICVIEW/vobs/DIRLEVEL1/DIRLEVEL2/SOMEFILE.cpp" to "/view/MYDYNAMICVIEW/vobs/DIRLEVEL1/DIRLEVEL2/SOMEFILE.cpp.contrib".
Output of merge is in "/view/MYDYNAMICVIEW/vobs/DIRLEVEL1/DIRLEVEL2/SOMEFILE.cpp".
Recorded merge of "/view/MYDYNAMICVIEW/vobs/DIRLEVEL1/DIRLEVEL2/SOMEFILE.cpp".
I never touched SOMEFILE.cpp - only ONE other developer ever changes it- why does it require a merge?
My net impression at the moment is that ClearCase's automatic merge is doing a bad job.
Could it be a good idea to think of using the "-qall" or "-qntrivial" options to disable ALL/MOST automatic merging -- and do EVERY/MOST merge manually? (or with an external tool?)
回答1:
1 & 2 How can this be possible???
This "Do you want the CHANGE made in file 2? [yes] no" message only appears when 2 contributors differ from the base contributor.
In that case, a cleartool lsvtree (not with -graph, since you don't have X-Window server) might help seeing the version involved, and trying to make some cleartool diff to see the difference (compared to the base contributor)
3/: that is one example where, if possible, working collaboratively on the same stream/branch (instead of working each developer in one own's stream) would be better.
Regarding the update of August 2015, the key error message is:
Missing charsets in String to FontSet conversion
See technote "Using GUI results in "Missing charsets in String to FontSet conversion" warning"
Possible causes include:
- An improper setting of the locale variable. For example it may be set to UTF-8.
- The file of interest is the Linux/palette, which defines the actual fonts used in the environment. This file is read to determine the fonts that can be displayed in the ClearCase GUI.
- The palette file does not contain the correct fontset.
This issue was identified as a product defect and logged under APAR PK30799.
来源：https://stackoverflow.com/questions/28911519/clearcase-merge-conflict-on-rebase-mystery-why-does-manual-merges-are-sometim