EPEL Amazon Linux and

[Christopher Meng]

Hi,

I've seen the thread of LLVM on Amazon, recently I received a report
that my package lnav doesn't work properly on Amazon Linux:

lnav: undefined symbol: _ZN7pcrecpp2RE4InitEPKcPKNS_10RE_OptionsE
> From the symbol I can see there should be a problem in pcre package.

Therefore here comes a question, what's the difference between
RHEL(CentOS) and Amazon?

Thanks.

Yours sincerely,
Christopher Meng

Noob here.

http://cicku.me

[Christopher Meng]

Ok, I just found the crux after sending this email.

[i@glusterfarm data]$ nm -aD /usr/lib/libpcrecpp.so.0 | grep Init
00002ed0 T _ZN7pcrecpp2RE4InitERKSsPKNS_10RE_OptionsE
         U _ZNSt8ios_base4InitC1Ev
         U _ZNSt8ios_base4InitD1Ev

The package in Amazon Linux is not the same version in RHEL. So
recompiling is needed.

Hence I'd like to suggest that we need to add some notes on the EPEL
wiki page, ideas?

Thanks.

[Matthew Miller]

On Fri, May 09, 2014 at 09:45:12AM +0800, Christopher Meng wrote:
> I've seen the thread of LLVM on Amazon, recently I received a report
> that my package lnav doesn't work properly on Amazon Linux:
> lnav: undefined symbol: _ZN7pcrecpp2RE4InitEPKcPKNS_10RE_OptionsE
> From the symbol I can see there should be a problem in pcre package.
> Therefore here comes a question, what's the difference between
> RHEL(CentOS) and Amazon?

Quite a lot; they make no attempt at compatibility. I think I'd respond with
that. EPEL packages might work on Amazon Linux, and they might not.

[Christopher Meng]

On Fri, May 9, 2014 at 9:57 AM, Matthew Miller  wrote:
> Quite a lot; they make no attempt at compatibility. I think I'd respond with
> that. EPEL packages might work on Amazon Linux, and they might not.

Matthew, thanks for your reply.

I took the info from the bug, and found that pcre on amazon linux is
8.x, quite fresh, RHEL only has 7.x version for customers.

So I believe it's worthwhile to add some notes on EPEL page to alert the
incompatibility.

[Dave Johansen]

On Thu, May 8, 2014 at 7:36 PM, Christopher Meng  wrote:
> On Fri, May 9, 2014 at 9:57 AM, Matthew Miller 
> wrote:
> > Quite a lot; they make no attempt at compatibility. I think I'd respond
>
> with
> > that. EPEL packages might work on Amazon Linux, and they might not.
>
> Matthew, thanks for your reply.
>
> I took the info from the bug, and found that pcre on amazon linux is
> 8.x, quite fresh, RHEL only has 7.x version for customers.
>
> So I believe it's worthwhile to add some notes on EPEL page to alert the
> incompatibility.

The EPEL is designed to support RHEL and its derivatives. Amazon Linux
seems to have started with EL6 as a base to at least some extent but has
since evolved significantly. They do have a FAQ (
https://aws.amazon.com/amazon-linux-ami/faqs/ ) and it does reference the
EPEL and how to use it, but it also talks about how it is "updated to
include the latest components on a regular basis". It also talks about how
there are several packages that are in Amazon Linux that are newer than
those in the EL6 and the EPEL.

Honestly, I think that the documentation of the issues with the EPEL
packages should really go on the Amazon side of things. They're the ones
that are deviating from EL and they should be letting their users know
about that instead of just saying "you can use the packages from EPEL". I
guess that doesn't preclude the EL/EPEL community from trying to be good
citizens and help users out with a little documentation, but I don't think
any significant amount of effort should be put into it.

Also, I'm not all that familiar with EC2 but it does appear that they do
have a EL offering ( http://aws.amazon.com/partners/redhat/ ) that should
be fully compatible with EPEL and that should definitely be proposed to
anyone that runs into issues using the EPEL. It also looks like there's
options for using CentOS as well ( http://wiki.centos.org/Cloud/AWS ), so I
think there are plenty of good options for those wanting to use the EPEL
and it just may not be that Amazon Linux is high on that list.

Dave

[Matthew Miller]

On Fri, May 09, 2014 at 10:36:11AM +0800, Christopher Meng wrote:
> So I believe it's worthwhile to add some notes on EPEL page to alert the
> incompatibility.

Something along the lines of: "EPEL is built on unmodified RHEL, and will
generally work on close rebuilds like CentOS. EPEL packages may not work on
distributions like Amazon Linux, which sometimes makes significant changes."

In the future, if CentOS "varients" catch on, this could be expanded to note
that those won't necessarily work either.