Binaries generated by perl's PAR::Packer break when packaged in RPM

Question

I have a perl script that I want to be usable on systems with no perl interpreter installed (like a linux container, for example). I generate a binary with PAR::Packer and everything appears to work great.

[0] [ishpeck@centbox03 /tmp/examply]$ file ./perlthing/scripts/hello.pl
./perlthing/scripts/hello.pl: Perl script, ASCII text executable
[0] [ishpeck@centbox03 /tmp/examply]$ cat ./perlthing/scripts/hello.pl
#!/usr/bin/perl
use strict;
use warnings;
use File::Basename;

print "Hello, world!\n"
[0] [ishpeck@centbox03 /tmp/examply]$ cat Makefile
CURDIR=/tmp/examply
TOPDIR=$(CURDIR)/packaging

rpm: perlbin
    sh -c 'for x in packaging/BUILD packaging/RPMS/x86_64 packaging/RPMS/x86 packaging/RPMS/arm packaging/SOURCES packaging/SPECS packaging/SRPMS; do mkdir -p $$x; done'
    rpmbuild --target x86_64 -bb $(TOPDIR)/SPECS/mypackage.spec --define '_topdir $(TOPDIR)' --define '_arch x86_64' --define '_working_dir $(CURDIR)'

perlbin: perlthing/binaries/hello.pl

perlthing/binaries/hello.pl: perlthing/scripts/hello.pl Makefile
    /usr/local/bin/pp -M File::** -M PAR:: --clean --verbose=2 --output=$@ $<

clean:
    rm perlthing/binaries/hello.pl

[0] [ishpeck@centbox03 /tmp/examply]$ make perlbin >/dev/null ; echo $?
0
[0] [ishpeck@centbox03 /tmp/examply]$ file perlthing/binaries/hello.pl
perlthing/binaries/hello.pl: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=7d5b38a792018d0202a96ce8645b00591e7ea7c5, stripped
[0] [ishpeck@centbox03 /tmp/examply]$ ./perlthing/binaries/hello.pl
Hello, world!

So far, so good. It even works when I copy the binary to a machine with no perl interpreter:

core@CoreOS-1 ~ $ which perl
which: no perl in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/opt/bin)
core@CoreOS-1 ~ $ ./hello.pl
Hello, world!

I want to package this in an RPM:

[0] [ishpeck@centbox03 /tmp/examply]$ cat packaging/SPECS/mypackage.spec
Name:           ishy-mypackage
Version:        0.1
Release:        1%{?dist}
Summary:        My example package

License:        MIT
URL:            http://ishpeck.net

%description
This is my example package that includes a perl script bundled as a binary via PAR::Packer

%prep
echo "Prepare scriptlet is empty"

%build
echo "Nothing really to do"

%install
rm -rf $RPM_BUILD_ROOT
mkdir -p $RPM_BUILD_ROOT/usr/local/bin/
cp %{_working_dir}/perlthing/binaries/hello.pl $RPM_BUILD_ROOT/usr/local/bin/

%files
/usr/local/bin/hello.pl
[0] [ishpeck@centbox03 /tmp/examply]$ grep rpmbuild Makefile
        rpmbuild --target x86_64 -bb $(TOPDIR)/SPECS/mypackage.spec --define '_topdir $(TOPDIR)' --define '_arch x86_64' --define '_working_dir $(CURDIR)'
[0] [ishpeck@centbox03 /tmp/examply]$ make 

But when I install the package, the perl binary doesn't work anymore!

[0] [ishpeck@centbox03 /tmp/examply]$ sudo rpm -i ./packaging/RPMS/x86_64/ishy-mypackage-0.1-1.el7.x86_64.rpm
[0] [ishpeck@centbox03 /tmp/examply]$ which hello.pl
/usr/local/bin/hello.pl
[0] [ishpeck@centbox03 /tmp/examply]$ hello.pl
Usage: /usr/local/bin/hello.pl [ -Alib.par ] [ -Idir ] [ -Mmodule ] [ src.par ] [ program.pl ]
/usr/local/bin/hello.pl [ -B|-b ] [-Ooutfile] src.par
Removing files in "/tmp/par-6973687065636b/temp-51174"
Undefined subroutine &File::Find::finddepth called at -e line 11.
END failed--call queue aborted at -e line 616.

I don't assume this is a problem with the way I'm using pp to generate the binary because it seems to work everywhere if I just copy it directly. My brain wants to place the blame on (how I use) rpmbuild but I don't even know where to begin with this.

Is there some arcane detail about rpmbuild that I'm missing here?

Answer 1

rpmbuild is stripping it

The default rpmbuild macros include strip commands that interfere with whatever magic PAR::Packer is doing.

If it take your sources I can reproduce the problem on CentOS 7, perl v5.16.3. Adding this at the top of your spec:

%global __os_install_post %{nil}

the binaries in the buildroot are unmodified and the program works. I'm not entirely sure why, you may want to ask Perl rpm maintainers or other Perl hackers for details.

---

Performance sidebar

I notice a consistent 100x slowdown of the packed binary compared to an actual perl interpreter. The difference may be less significant for non-trivial programs. Even this trivial build is 4 MB in size.

I can appreciate bringing the power of the Swiss-Army chainsaw to unenlightened distros, but note that a native binary is unlikely to be a performance boost.