rm /etc/make.conf - oops [SOLVED + HOWTO]

sobani · n00b Joined: 12 May 2007 Posts: 5

Ok, I've been kinda stupid. I accidentally removed make.conf when I actually wanted to remove make.profile. And of course I also have no backup of it anywhere. (this is why)

I see two possibilities for getting my make.conf back, reverse the remove command and resurrect all settings from the current state of my installation.

I'm using ReiserFS as file system. I know it logs the transactions in case of a power outage or something. Maybe it still has that fatal remove command in its logs, ready to reverse that, but I doubt it. From what I know of removing files though, is that it only removes the reference, not the data. So unless that is already destroyed by writing to another file, it should be possible to put the reference back to that chunk of data, right? Anyone knows how to do that?

So while ago I put many hours in removing and adding the use flags in a fashion that looked nice to me. So just replacing make.conf with the default file is not going to do that trick. I also know that you can see the use flags that are different when you do a "emerge -pve world". It's just that that list is a bit long and tedious to go through. Is there any way to see all the use flags that I once used, without all the packages? Or does someone know some regular expressions to make a list of the use flags from the emerge command?

Please help this luser-with-a-root-password.

sobani

NeddySeagoon · Posted: Sat May 12, 2007 4:42 pm Post subject:

sobani,

Welcome to Gentoo.

There is normally no undelete in the *NIX world as it would be a security issue. One user could undelete another users (even roots) deleted files. You can scan the 'empty' partition space for a file fragment that you expect to find and recover something that way.

As its your USE flags that are most of the work, it will be faster to recreate them with ufed and the output of emerge -evp world, as you have already suggested.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

sobani · n00b Joined: 12 May 2007 Posts: 5

NeddySeagoon · Posted: Sat May 12, 2007 5:57 pm Post subject:

sobani,

OK, I admit I managed to do

sobani · n00b Joined: 12 May 2007 Posts: 5

How to recover /etc/make.conf

0. Calm down

Remember that it isn't all lost. emerge --pretend --verbose will tell you that you're going to install that critical package without the great gnome support and with support of that *censored* kde. - Although, if you abuse root powers, maybe you deserve the extra 10GB kde libraries download.
0.1 For kde lovers; calm down.

1. emerge ufed
ufed is a nice tool to tweak the use flags in your make.conf. It doesn't recognize all the flags available, but that's a concern for later.

2. cp /etc/make.conf.example /etc/make.conf
Alas, you have no make.conf, remember? So from now on you do have one. Yay!
2.1 If you like the "-*" flag, like I do, use ufed and select it now.

3. emerge --pretend --verbose --emptytree world > /tmp/world-all
Let's save a snapshot of all the packages you have installed at this moment. Now you need to screw up two more times to really lose hope of recovering your make.conf. Consider backing up this file though.

3.1 If it takes more than a minute or so, reassure yourself that you didn't forgot about the --pretend flag. Certainly don't wait until next morning for this command to finish.
3.2 Take a good look at the packages it can't find. Maybe you have to add some portdir overlays? Find the howto about those packages and add the parts they tell you you have to add to make.conf.

4. cat /tmp/world-all | grep USE | sed -e 's/USE=\"//;s/\".*//;s/ /\n/g' | grep "*" | sort -u
This will give you a list of all the use flags we care about at this moment. It starts with reading /tmp/world-all. Then it selects all lines that contain the word "USE". Thereafter everything before and after the use flags gets stripped and all spaces get converted to newlines. Now there is one use flag per line of text. With grep only the lines which contain a * are kept and the sort -u command will make sure that you only see every use flag once.
Now we have a list of all use flags that are different compared to the current broken state of your machine. Remember them, write them down or start another terminal session.
thanks to Think4UrS11 for showing me (parts of) how to pull this off

5. ufed
Now you can finally start to set things right in make.conf. Take your list and select every flag that says "-use*" in your list. Unselect every flag that says "use* in your list. Remember that the use flags with the star are the flags that are going to be changed to the state in which they are presented.
5.1 edit /etc/make.conf
There are flags that ufed doesn't recognize. And I haven't figured out how to let ufed disable flags, other than using "-*". Find the part where it says 'USE="..." '. The use flags are likely to be spread over multiple lines. Now you have to add all the flags that ufed didn't recognize and remove all use flags that you couldn't unselect.

6. repeat step 2 to 7.1
For some reason one of the packages was merged with USE="-X" and without a /etc/portage/packages.use line. Of course the "X" use flag is pretty obvious, but you can't be sure about all of them. Repeating everything will show up those odd use flags again.

7. cat /tmp/world-all | grep "VIDEO_CARDS"
All the changed use flags may be done now, but the VIDEO_CARDS settings probably need a change too. I couldn't find these in the default make.conf file, so you will have to add it yourself. Remember however that unlike USE, you can't use a minus. You will have to add every flag you want and leave out the ones you don't.
7.1 cat /tmp/world-all | grep "INPUT_DEVICES"
The same deal as with VIDEO_CARDS.
7.2 If those settings don't need a change, it might be a nice idea to change these later on. Or don't, this is a howto about recovering make.conf, not about breaking it. At least don't make changes at this point. Never ever combine recovering with changing settings. If something gets broken in the total process it will be a lot harder to figure out what did it.

8. emerge --pretend --verbose --update --deep --newuse world
This one should come out empty. If it doesn't, take a good look at the list it shows you. You might want to start from step 2 again if you don't like the look of it. At least don't move forward until this list is either empty, or shows only the settings the way you want them.
Oh, and all flags with a % are flags that are new for that package since its last merge. Don't worry about those.

9. read /etc/make.conf
Take your time to take a look at make.conf. Maybe you need to change CHOST? Or you don't like the default CFLAGS? I can't help you with these ones though. You'll have to figure them all out again. In case of the CFLAGS it probably wouldn't mind if you forgot a few of those 'optimizing' flags though. Although entering every possible flag you can find might break rm too.

10. backup your /etc/make.conf
You're going to do it this time, right? ... Heh, me neither.
10.1 repeat step 12 until you feel comfortable to touch the rm command again.

11. Apologize to your PC
Some might find this a little late, but I prefer to set things right first, and then apologize.

12. rm /tmp/world-all /tmp/world-use
Or don't. You might end up doing "rm /var/lib/portage/world".

Well, you should have your make.conf file recovered now. Good luck and be careful with rm.

ppurka · Advocate Joined: 26 Dec 2004 Posts: 3256

Care to put this elaborate procedure in the Documentation Tips and Tricks forum? You could ask a mod to move this particular post to that forum.
_________________
emerge --quiet redefined | E17 vids: I, II | Now using kde5 | e is unstable :-/

NeddySeagoon · Posted: Sun May 13, 2007 12:40 pm Post subject:

Moved from Other Things Gentoo to Documentation, Tips & Tricks.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

steveL · Posted: Sun May 13, 2007 1:23 pm Post subject: Re: How to recover /etc/make.conf

think4urs11 · Posted: Sun May 13, 2007 1:48 pm Post subject: Re: How to recover /etc/make.conf

sobani · n00b Joined: 12 May 2007 Posts: 5

steveL · Posted: Tue May 15, 2007 3:23 pm Post subject: Re: How to recover /etc/make.conf

steveL · Posted: Tue May 15, 2007 4:47 pm Post subject:

Nanafunk came up with this beauty:

franckspike · n00b Joined: 16 May 2023 Posts: 1

In my case the "emerge --pretend ... > /tmp/world-all" command failed.

So I just restarted a make.conf from scratch following the Gentoo installation guide
1 - at https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Stage
2 - then https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Base

I made sure these vars were properly set

GENTOO_MIRRORS
GRUB_PLATFORMS
VIDEO_CARDS
CHOST
COMMON_FLAGS="-march=native -O2 -pipe"
CFLAGS="${COMMON_FLAGS}"
CXXFLAGS="${COMMON_FLAGS}"
MAKEOPTS

And then I used this command

emerge -uaDN @world # then Ctrl-C to cancel... probably --pretend is better than -a here...

to find which use flags portage thought I changed

Then I added them back in my make.conf

and I did this in a loop a few times until all the USE flags returned to the originals.
That is when emerge thought no package needed to be built
(my system was near up-to-date before the truncation to 0 bytes of my make.conf file)

I hope this can help ! :-)

ZekeMorrin · n00b Joined: 15 Oct 2023 Posts: 13

I generally post my /etc/portage/make.conf file here https://forums.gentoo.org/viewtopic-t-541850.html -almost two decades old topic from this forums- if I need to make some big changes like new pc etc.

So while I install Gentoo, I always check that post at some point. And I never lose it too this way.