Copying dd from RHEL4 and running on RHEL5 ran successfully when just copying the binary, as well as when packaged with RHEL4's libc and ld-linux. Due to some crazy company policy restrictions, I packaged these by hand rather than using stratifier or Ermine.

Happily, though, I have realized that we have another alternative that karhel didn't: we are building the applications that need to run on multiple distributions/versions. Because of this, we're going to investigate the possibility of building on a newer version and verifying compatibility on older ones.

Thanks for the thoughts! I'm very impressed by getting a response on this thread! I will definitely post the results of our further attempts.

Hello

The only solution we found to solve our issue was to create a VM in RHEL4 to use our old software.

B/R
KarHel

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Good to know. Thanks for the update (and nice memory)! Things are good for us building on RHEL5, packaging necessary shared objects (including ld-linux), and then running on RHEL4 (and others). Still curious why going the other way doesn't seem to work, but we'll be content with this approach.

Thanks again!

Hello. I found this thread on stackoverflow:
http://stackoverflow.com/questions/1...t-main-return0

Looks like the problem boils down to the following: ld.so on RHEL5 uses ONLY GNU_HASH.
This section is not present in executables built for RHEL4, so ld.so can't find information
it supposed to find.

Could you check if it's indeed you case?

Actually, I had found that stackoverflow topic as well. Unfortunately, I didn't really understand what they were talking about well enough for me to implement any change. What is "readelf" really being run on? What did it mean to "look for a GNU_HASH"? When I ran readelf on my executable, I couldn't find GNU_HASH in the results anywhere. Which, I suppose, wasn't surprising.

Then, the build options that were recommended ... are those compiler or linker options? I believe they're compiler options. However, I didn't have the motivation to try them, since our build environment is pretty crazy. Switching platforms was simpler than adding compiler options. :/

Still, because I'm impressed by the help I've received, I tried compiling one of our applications with -Wl,--hash-style=both on RHEL4. This resulted in an error:
/usr/bin/ld: unrecognized option '--hash-style=both'
Same error with sysv:
/usr/bin/ld: unrecognized option '--hash-style=sysv'

So, again, I'm not quite sure what's going on. But I am content with building on RHEL5, as that build runs everywhere that we need it to.