Screen: “Cannot exec /my/path/to/zsh” with local shell

Question

Whenever I try to run screen under a Zsh shell that I compiled under my home directory, I get the following error:

> screen
Cannot exec '/my/path/to/zsh/bin/zsh'

The Z shell is perfectly functional, and I have verified that I can run screen if I invoke it using a system shell (e.g. csh). I usually get into zsh with: exec zsh. Here is some additional info about my system:

> echo $SHELL
/my/path/to/zsh/bin/zsh

> echo $ZSH_VERSION
5.0.0

> which screen
/usr/bin/screen

> screen --version
Screen version 4.00.03 (FAU) 23-Oct

My .screenrc just has two lines in it:

escape ^A^A
bind o other

In case it matters: /my/path/to/zsh/ refers figuratively to a path under my home directory.

Update

1. Output of calling file:

   > file /my/path/to/zsh/bin/zsh
   > /~/sw/zsh/bin/zsh: ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for
   > GNU/Linux 2.6.9, dynamically linked (uses shared libs), 
   > for GNU/Linux 2.6.9, stripped
   

2. But I can successfully run /my/path/to/zsh/bin/zsh and enter zsh from my csh shell. I usually switch to zsh with exec /my/path/to/zsh/bin/zsh

3. Below are the ls details on /my/path/to/zsh/bin/zsh

   -rwxr-xr-x 2 YYYY ZZZZ 651K Jan 3 11:58 zsh*
   

4. Mi .login is empty (it only has comments on it)

5. I don't have a .profile file

6. cat/etc/*-release:

   Scientific Linux SL release 5.1 (Boron)
   

Any thoughts on what may be causing this and how to get screen to work with my local installation of zsh?

Answer 1

One possible reason is that screen is privileged (on some systems, it's setgid utmp, to be able to log terminal ownership to the utmp file), and that this zsh binary needs a library that isn't in the default library path. Calling a setuid or setgid program erases some environment variables, in particular LD_LIBRARY_PATH.

If you can execute /my/path/to/zsh/bin/zsh from outside screen but not from inside, and you're setting LD_LIBRARY_PATH in your .profile, that would explain your symptoms.

Answer 2

This is embarrassing: the value of of my $SHELL variable was not correct (it had a typo). I apologize - I will make sure I triple check these things before posting a question like this and wasting everyone's time. Thanks so much to all for your help.