致命的：无效的refspec'+ refs / heads / *'

Question

In git-fetch doc, you can see:

The remote ref that matches <src> is fetched, and if <dst> is not empty string , the local ref that matches it is fast-forwarded using <src>. If the optional plus + is used, the local ref is updated even if it does not result in a fast-forward update.

So we can use empty string as destination . Now my current repository has a remote which it's name is origin . When I try to fetch like this, I get an error:

git fetch origin +refs/heads/*
fatal: Invalid refspec '+refs/heads/*'

But why an empty string cause invalid refspec ?

Answer 1

When I try to fetch like this, I get an error:

You don't need to supply information to the fetch this way.

You can use it like this (no need to define the ref themself):

# fetch all ref
git fetch 

# fetch a specific ref
git fetch origin 

The format of a parameter is an optional plus +, followed by the source ref , followed by a colon :, followed by the destination ref . The colon can be omitted when is empty.

Answer 2

The refspec descriptions in all of the git documentation are generally a bit poor, in part because all this stuff evolved over time and the current best practice refspecs were only invented for git version 1.5, with older methods still being supported today.

In any case, shell glob style * matches are limited ( less so in git 2.6 than they were before). One limitation is requiring full pairs: That is, you cannot use a wildcard match * on the left side of a fetch refspec without having a corresponding * on the right. This is why git winds up rejecting your empty refspec, even though it should logically work on the command line (in that it should be able to drop any matching ref into FETCH_HEAD ).