Using ‘--strip-all’ instead of ‘--strip-debug’?

[Ludovic Courtès]

Hello Guix!

A while back Dave Love (IIRC) suggested stripping binaries with
‘--strip-all’ instead of ‘--strip-debug’.  I found traces of a previous
unfruitful experiment in that area as shown in this commit:

  commit 7da473b75721e06237b106c6d186f2729117b1ee
  Author: Ludovic Courtès <address@hidden>
  Date:   Mon Dec 29 21:44:48 2014 +0100

      gnu: Revert use of '--strip-all'.

      This reverts commits f05bdc9412135f34a1c417edc203c35cd005d0d5
      and 856ae5e6c71a1283a414d33e638051f95d3cce35.

      This broke all sorts of things.  See <http://hydra.gnu.org/eval/102058>,
      for example.

Unfortunately, the Hydra URL above is no longer available and I have no
idea what broke exactly.

The patch below reverts the revert.  I’ve built Coreutils, Git, and Node
on top of ‘core-updates’ with it.  Here are the sizes compared to master:

--8<---------------cut here---------------start------------->8---
$ ./pre-inst-env guix size git | tail -1
total: 354.6 MiB
$ guix size git | tail -1
total: 364.5 MiB
$ ./pre-inst-env guix build -e '(@@ (gnu packages commencement) 
coreutils-final)'
/gnu/store/6mvaqb321wsxgb6v1rddczpd0n4b2x6g-coreutils-8.29-debug
/gnu/store/n7911c84mipr2qjp6vjqj1mbih5xysrk-coreutils-8.29
$ guix size /gnu/store/n7911c84mipr2qjp6vjqj1mbih5xysrk-coreutils-8.29 | tail -1
total: 77.7 MiB
$ guix build -e '(@@ (gnu packages commencement) coreutils-final)'
/gnu/store/l890vkp8mj07r9faglddwkpf7w33w71y-coreutils-8.28-debug
/gnu/store/6i33ik7haav0hd5a797l3llkq04ghx6g-coreutils-8.28
$ guix size /gnu/store/6i33ik7haav0hd5a797l3llkq04ghx6g-coreutils-8.28 | tail -1
total: 78.9 MiB
$ ./pre-inst-env guix size node | tail -1
total: 194.6 MiB
$ guix size node | tail -1
total: 201.9 MiB
--8<---------------cut here---------------end--------------->8---

So we’re talking about a 1.5–3.6% improvement on the whole closures,
which is quite disappointing.

If we look at Coreutils and Git alone (not the closure), we gain 7.3%
and 8.9% respectively (for reference, Coreutils in Debian is at 14.7 MiB
per <https://packages.debian.org/sid/coreutils>):

--8<---------------cut here---------------start------------->8---
$ guix size /gnu/store/n7911c84mipr2qjp6vjqj1mbih5xysrk-coreutils-8.29 | grep 
coreutils
/gnu/store/n7911c84mipr2qjp6vjqj1mbih5xysrk-coreutils-8.29          77.7    
13.9  17.9%
$ guix size /gnu/store/6i33ik7haav0hd5a797l3llkq04ghx6g-coreutils-8.28 | grep 
coreutils
/gnu/store/6i33ik7haav0hd5a797l3llkq04ghx6g-coreutils-8.28          78.9    
15.0  19.0%
$ ./pre-inst-env guix size git | grep git-2.16
/gnu/store/f4bwbv3clbyz5snjfbq7wzrxlvj0rwwh-git-2.16.2             354.6    
31.4   8.9%
$ guix size git | grep git-2.16
/gnu/store/jwbc0rnn7qa4064bghqs7q8r0bm7v32p-git-2.16.2             364.5    
34.5   9.5%
--8<---------------cut here---------------end--------------->8---

We get 9.8% for Node (it’s C++, so it has bigger symbol tables I guess):

--8<---------------cut here---------------start------------->8---
$ ./pre-inst-env guix size node | grep node
/gnu/store/iwdhzvdqjfqfd0m62f6z8a6sxqzb24cr-node-9.4.0             194.6    
44.0  22.6%
$ guix size node | grep node
/gnu/store/rk8is4gw40w9dbzj6q3313z7ly34mj62-node-9.4.0             201.9    
48.8  24.2%
--8<---------------cut here---------------end--------------->8---

The main downside is unexpected breakage as the 2014 commit above
suggests (would “--strip-debug --strip-unneeded” be safer?).

Thoughts?

Ludo’.

0001-build-system-gnu-Strip-with-strip-all-instead-of-str.patch
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