This is a very specific and niche question- but something that'll probably help people working on existing codebases.
Current Scenario
We are running ejabberd 18.01 on prod- and we can't really change this right away. Our current setup for running custom modules is this- either modify existing modules from the source code, or make our own custom modules that are compiled using the erlang compiler that's bundled in with the installer from here. We use erlide as our IDE in Eclipse.
We compile the custom files in in erlide, into a separate directory from where our ejabberd .beam files are; and then transfer the files manually from there to the ebin folder in ejabberd. This is done so that we have VCS for our modified module files.
We aren't using rebar3, and I have zero clue as to how to implement in a heavily modified existing codebase without breaking something. Our only legitimate way of debugging is to put loggers at every step of the process, compile, transfer files, and restart the server- which drastically increases dev time.
It is a genuine nightmare to work with, and resources on ejabberd as well as erlang is scarce- we mostly have the docs to go by, and barely any SO questions relevant.
Any suggestions, resources that can help me setup something to help especially for debugging, would be highly appreciated. Maybe something in vscode would be great. Transferring files I've still managed with inotify, but debugging makes me want to tear my hair out. Please help. Thank you.
P.S.- This is all on Ubuntu 20.04, if relevant. Erlang/OTP version - 20.02, erts- 9.2. Please ask for any further clarifications if required.
This is making absolutely no sense to me: I just installed crosstool-ng and I need to install the gcc-arm-linux cross-compiler toolkit on my mac. I used ct-ng arm-unknown-linux-gnueabi and it worked fine. Next step was ct-ng build, which I followed. It resulted, however, in this error.
Your file system in '/usr/local/GCC-ARM-Linux-GNUeabi/.build' is *not* case-sensitive!
I am lost and it's imperative that I install the toolkit in order to cross-compile for a Linux-based micro-controller for a project I'm in.
Managed to fix it by partitioning the disk, creating a small space that was case-sensitive. Basically, I followed this tutorial. This problem and some subsequent ones I was able to fix. However a wild new problem appeared. But that is the subject of another question.
I'm trying to use MPU3000/3050 by Invensense with embedded linux (ARM-based LPC3141 board, Embedded Artists).
I found this interesting patch on the Internet
https://patchwork.kernel.org/patch/703991/
how can I implement it in my kernel?
Read this article for detailed instructions on how to apply a patch.
Warning: kernel patches are quite often highly specific to the version of Linux they were developed for, so if your kernel version is different from the one the patch was originally made for you may encounter some problems.
Edit: I had a look at this particular patch and essentially it creates a new file (mpu3050.c) and modifies drivers/input/misc/Makefile and drivers/input/misc/Kconfig. Even if everything else fails the new file should be created, and the mods to the existing files can probably be done manually.
I don't know about the details, but you should download the kernel from www.kernel.org, patch it with the 'patch' utility and configure it to compile it. You should search some manuals for the configuration.
I am not sure if you already knew this, though.
I'm wrote an application and I need to execute it on Gentoo,
but when I try run it, I get the following message:
/lib/libc.so.6: version `GLIBC_2.3.4' not found (required by /usr/local/myapp/lib/myapplib.so.1)
the current GLIBC version in this gentoo is 2.3.2.
I can't update this glibc, because I don't have permission, so I need to 'downgrade'
my glibc to the same version (2.3.2) ... how can I do it?
tks,
The "/lib/libc.so.6: version `GLIBC_2.3.4' not found" problem comes from trying to run a binary compiled against a newer glibc on a system with an old version of glibc. Downgrading glibc is strongly discouraged for this reason.
Since you say you wrote the application, it seems to me that the simplest solution is to recompile the application on the system where you plan to run it.
I'm actually wrestling with the same issue, so maybe I have some information that can help.
In short, your binary was compiled to look for libc.so.6. GLIBC_2.3.4 is in libc.so.5. As far as I know, if you downgrade your glibc on your dev machine some of your other programs may not work properly (because they were compiled to look for the current version). Somehow CentOS/RHEL have a compat-glibc package that can live along side of a current glibc without causing this error. If your dev box uses CentOS/RHEL, install that package/recompile and you should be good to go. You may need to use an older compiler for it to look for the older library. If you're not developing on CentOS/RHEL, continue on.
My plan of attack today is to compile glibc from source. This means using a compiler that was released around the same time as the older version of glibc. You may run into some stumbling blocks (such as needing an older version of buildutils, etc.), but my hope is once the libc.so.5 is compiled and installed into /usr/local/lib my application will find that before it finds libc.so.6 in /lib.
So there it is. It's not for the faint of heart, and it's definitely not a quick solution. Today I plan on testing this out, so I can't really say it's the right solution. Please, hivemind.. if I'm flat-out wrong correct me and save this poor soul from this winding torturous road :-)
EDIT: link to glibc sources
At work I'm using Perl 5.8.0 on Windows.
When I first put Perl on, I went to CPAN, downloaded all the sources, made a few changes (in the .MAK file(?) to support threads, or things like that), and did nmake / nmake test / nmake install. Then, bit by bit, I've downloaded individual modules from CPAN and done the nmake dance.
So, I'd like to upgrade to a more recent version, but the new one must not break any existing scripts. Notably, a bunch of "use" modules that I've installed must be installed in the new version.
What's the most reliable (and easiest) way to update my current version, ensuring that everything I've done with the nmake dance will still be there after updating?
As others noted, start by installing the new perl in a separate place. I have several perls installed, each completely separate from all of the others.
To do that, you'll have to configure and compile the sources yourself. When you run configure, you'll get a chance to specify the installer. I gave detailed instructions for this in an "Compiling My Own Perl" in the Spring 2008 issue of The Perl Review. There's also an Item in Effective Perl Programming that shows you how to do it.
Now, go back to your original distribution and run cpan -a to create an autobundle file. This is a Pod document that lists all of the extra stuff you've installed, and CPAN.pm understands how to use that to reinstall everything.
To install things in the new perl, use that perl's path to start CPAN.pm and install the autobundle file you created. CPAN.pm will get the right installation paths from that perl's configuration.
Watch the output to make sure things go well. This process won't install the same versions of the modules, but the latest versions.
As for Strawberry Perl, there's a "portable" version you can install somewhere besides the default location. That way you could have the new perl on removable media. You can test it anywhere you like without disturbing the local installation. I don't think that's quite ready for general use though. The Berrybrew tool might help you manage that.
Good luck, :)
I would seriously consider looking at using Strawberry Perl.
You can install a second version of Perl in a different location. You'll have to re-install any non-core modules into the new version. In general, different versions of Perl are not binary compatible, which could be an issue if you have any program-specific libraries that utilize XS components. Pure Perl modules shouldn't be affected.
If you stay within the 5.8 track, all installed modules that contain XS (binary) extensions will continue to work, as binary compatibility is guaranteed within the same 5.8 series. If you moved to 5.10 then you would have to recompile any modules that contain XS components.
All you need to do is ensure that the new build lists the previous include directories in its #INC array (which is used to look for modules).
By the sounds of it, I think you're on Windows, in which case the current #INC paths can be viewed with
perl -le "print for #INC"
Make sure you target your new Perl version in another directory. It will happily coexist
with the previous version, and this will allow you to choose which Perl installation gets used; it's just a question of getting your PATH order sorted out. As soon as a Perl interpreter is started up, it knows where to look for the rest of its modules.
Strawberry Perl is probably the nicest distribution on Windows these days for rolling your own.
I think the answer to this involves virtualisation of some kind:
Set up an exact copy of your current live machine. Upgrade Perl, using the same directory locations and structures as you're using at the moment.
Go through your scripts testing them on the new image.
Once you're happy, flip the switch.
The thinking behind this is that there's probably all sorts of subtle dependencies and assumptions you haven't thought of. While unlikely, the latest version of a particular module (possibly even a core module, although that's even more unlikely) might have a subtle difference compared to the one you were using. Unless you've exhaustively gone through your entire codebase, there's quite possibly a particular module that's required only under certain circumstances.
You can try and spot this by building a list of all your scripts - a list that you should have anyway, by dint of all your code being under version control (you are using version control, e.g. Subversion, yes?) - and iterating through it, running perl -c on each script. e.g. this script. That sort of automated test is invaluable: you can set it running, go away for a coffee or whatever, and come back to check whether everything worked. The first few times you'll probably find an obscure module that you'd forgotten about, which is fine: the whole point of automating this is so that you don't have to do the drudge-work of checking every single script.
When I did it I installed the newer one into a separate directory. There's a bit of added confusion running two versions, but it definitely helps make sure everything's working first, and provides a quick way of switching back to the old one in a pinch. I also set up Apache to run two separate services, so I could monkey around with the newer Perl in one service without touching the production one on the old Perl.
It's probably a lot wiser, in hindsight, to install on a separate computer, and do your testing there. Record every configuration change you need to make.
I am not sure about building it yourself—I always just used prepackaged binaries for Windows.
I'm not sure I understand exactly what you're asking. Do you have a list of changes you made to the 5.8 makefile? Or is the question how to obtain such a list? Are you also asking how to find out which packages above the base install you've obtained from CPAN? Are you also asking how to test that your custom changes won't break those packages if you get them from CPAN again?
Why don't you use ActivePerl and its "ppm" tool to (re)install modules?