Just strip everything by default

[layus]

Stripping binaries is of utmost importance to benefit from the closure-size changes.
To avoid missing custom paths (like /modules for php-like packages), strip the whole output.

This PR has the following advantages

1. It does not produce pointless warning about unrecognized filetypes;
2. It does strip everything that strip can strip;
3. It does not ignore failures of strip (other than unrecognized filetypes).

I have tested it on some derivations (ldb, php) by fiddling around with makeSetupHook, but not on stdenv. That being said, the only way this patch could break stuff is by stripping something that should not be stripped and that resides outside of lib lib32 lib64 libexec bin sbin.

NB: This triggers a mass-rebuild.
Fixes #14821, #14822, #14823, #14824.

[mention-bot]

By analyzing the blame information on this pull request, we identified @edolstra to be a potential reviewer

[danbst]

When this is merged some dontStrip properties can be removed from expressions. I've used dontStrip exactly to shut up file format warnings

[edolstra]

Looks good to me.

[layus]

Thanks for the reviews.
I have a few questions: Is staging the right branch to pull-request against for this impacting change? And what is the usual policy for merging mass-rebuild changes? I assume we try to group them and merge a bundle now and then, right?

[globin]

It is the right branch, normally someone looks through the mass-rebuild changes and merges them about once a week.

[peti]

Merged to staging in 2362891.

[peti]

Hmm, the error https://travis-ci.org/NixOS/nixpkgs/builds/127459031#L1131 looks a little disconcerting. @layus, have you tested the bootstrapping process with your patch applied?

[layus]

That was fast :-). No, as I explain above, I have done little testing on this (because I do not know how, except rebuilding my whole system). I actually started a nix-build -A stdenv and stopped it after some time because everything was going well. Not much of a test.

Now, I have no idea how a line like mkdir: cannot create directory '/nix-support': Permission denied can be related to this. I can however reproduce the bug locally with a simple nix-build -A zlib on branch staging.
Trying to investigate the issue...

[layus]

More info:
The setup script has (/nix/store/2fcjgppcvy54l1j7mk4iirg46az9q7iw-stdenv-linux-boot/setup, line 774):

    if [ -n "$setupHook" ]; then 
        mkdir -p ${!outputDev}/nix-support"
        substituteAll "$setupHook" "${!outputDev}/nix-support/setup-hook"
    fi

which fails because

1. paxctl had a setupHook, and
2. somehow, ${!outputDev} is empty.

Looking further...

[layus]

@peti, Look no further, the issue is obviously in the patch as it overrides $out

+            if out=$(strip $commonStripFlags $stripFlags "$f" 2>&1); then

I need to make my variables local!
I will submit a better version soon, but feel free to do it before me if you feel so.

[peti]

I'd prefer to get a fix.

[peti]

I reverted the patch in 397c75a.

[layus]

Yes, seems better as the fix has complications.
Now that I am testing it properly, it appears that stripping an empty file for example is not safe.
if the file contains only a line break, then strip fails with a "File truncated" error.

So this patch also requires small adjustments in other derivations.

[layus]

Somehow, I lost track of this branch and GitHub won't let me push commits to it.
The new version is in #15339.

@peti, the new version has been fully tested. It does not break stdenv and updates the manual \o/.