Git conflict “both deleted”

As stated in this answer (suggested as a duplicate) :

you can see a “both deleted” when branchA has a git mv oldfile newstandard commit, and branchB has a git mv oldfile newcustom commit.

In that case, when trying to merge customBranch into standardBranch, git will report a conflict on three files :

both deleted:  oldfile
added by them: newcustom
added by us:   newstandard

Like any conflict, the final choice resides in your hands :

git merely highlight the fact that maybe there could be a problem in the fact that newcustom and newstandard live together in your final code version, and maybe this could be linked to the fact that both were created by being a copy of oldfile.

You get to manually fix that :

• if removing oldfile is the expected outcome : git reset -- oldfile,
• if keeping newstandard is the expected outcome, remove the other : git reset newcustom && git rm newcustom,
• if some parts of newstandard and newcustom should be merged : edit them by hand, or use a 3-way merge tool : meld newstandard newstandard newcustom
• etc …