How to bump a package version locally?

[Hiep Pham <hiepph9@proton.me>]

Hi,

I want to bump `jsonnet` version from 0.17.0 to 0.20.0 from the master 
branch of the `guix` repository. I edited the version in 
`gnu/packages/cpp.scm`:

(define-public jsonnet
   (package
     (name "jsonnet")
     (version "0.20.0")
     [snip]
   ))

*How do I test building/installing this change locally?*
Here what I tried so far:

1. Standing at the root of the `guix` repository, build with:

guix build -L . jsonnet

This failed:

```
guix build: warning: failed to load '(build-aux build-self)': 
 

no code for module (build-aux build-self) 
 

./build-aux/build-self.scm:19:0: warning: module name (build-self) does 
not match file name 'build-aux/build-self.scm' 

hint: File `./build-aux/build-self.scm' should probably start with: 
 

 
 

      (define-module (build-aux build-self)) 
 

 
 

guix build: All 92 channel news entries are valid. 
 

guix build: warning: failed to load '(build-aux check-channel-news)': 
 

no code for module (build-aux check-channel-news) 
 

hint: File `./build-aux/check-channel-news.scm' should probably start 
with: 

 
 

      (define-module (build-aux check-channel-news)) 
 


[snip] 


guix build: warning: failed to load '(build-aux compile-all)':
```

2. Followed the contributing guide [1], I created a shell instead:

guix shell -C -D guix git help2man strace
./bootstrap
./configure --localstatedir=/var

This generated `pre-inst-env`, but `make` step failed with:

```
   MAKEINFO doc/guix.de.info
contributing.de.texi:1659: @menu reference to nonexistent node 
`Configuring Git'
contributing.de.texi:1660: @menu reference to nonexistent node `Sending 
a Patch Series'
make[2]: *** [Makefile:5003: doc/guix.de.info] Error 1
```

So I was blocked to progress further :(


[1] https://guix.gnu.org/manual/en/guix.html#Contributing

-- 
Hiep