Re: Golang programs keeping references [gnu: go: Update default to 1.11.]

[Ludovic Courtès]

Hello!

Pierre Neidhardt <address@hidden> skribis:

> I've investigated the possible solutions to avoid including the paths into the
> binaries.
>
> I've found this:
>
> https://github.com/golang/go/issues/16860
>
> It's still unresolved and only planned for Go 1.13.
>
> In the meantime, I've played with the -trimpath option to see if I could get
> something out of it.
>
> I've added this to Go's (build) function:
>
>               "-asmflags=all=-trimpath=/gnu/store"
>               "-gcflags=all=-trimpath=/gnu/store"
>
> The resulting binary is indeed trimmed, but that's not enough: it seems that
> Guix detects the remaining part of the path as a store item and includes it in
> the list of requisites.  Is this really how Guix works?  It does not need the
> full path?

No, the scanner just looks for the hash part of the store file name (see
‘scanForReferences’ in nix/libstore/references.cc).

How much of a problem is this though?  Currently the set of references
looks reasonable:

--8<---------------cut here---------------start------------->8---
$ guix size go-ipfs
store item                                                       total    self
/gnu/store/rm3cfgzd8iywjmsdcxf6gnwswm5za50x-go-ipfs-0.4.18         203.4   
102.2  50.2%
/gnu/store/h90vnqw0nwd0hhm1l5dgxsdrigddfmq4-glibc-2.28              37.8    
36.3  17.8%
/gnu/store/ypiv8dj4lkvsnm82s639h18l87frrh5g-gcc-6.5.0-lib           69.0    
31.2  15.3%
/gnu/store/4sqps8dczv3g7rwbdibfz6rf5jlk7w90-gcc-5.5.0-lib           68.0    
30.2  14.8%
/gnu/store/8g2wi0i5fgp0ylz99mckhprh25p1zgiv-tzdata-2018e             2.0     
2.0   1.0%
/gnu/store/zzakf905mzla4csi1dn9qpcwmgbxj29b-bash-static-4.4.23       1.5     
1.5   0.8%
/gnu/store/sj8m05bfj2902h67c4qkmvnzg2pjdgsv-net-base-5.3             0.0     
0.0   0.0%
total: 203.4 MiB
--8<---------------cut here---------------end--------------->8---

Well OK we could do with a single gcc:lib :-), but other than that it
looks good.

Thoughts?

Ludo’.