Hello, simply adding <Perl> $[ </Perl> to /etc/apache2/apache2.conf (or PerlPostConfigRequire a file containing $[) causes apache to segfault (trace below).
Strangely this happens _only_ if mod_php is also loaded! No sane person cares about $[, but it's not uncommon to PerlPostConfigRequire some old module using it, and it took me a few hours to figure out what's happening after upgrading to ubuntu 15.04. Tested in a clean ubuntu 15.04 installation: apache 2.4.10 perl 5.20.2 mod_perl 2.0.9~1624218 mod_php 5.6.4 Cheers, Kostas 2. Used Components and their Configuration: *** mod_perl version 2.000009 *** using /usr/lib/x86_64-linux-gnu/perl5/5.20/Apache2/BuildConfig.pm *** Makefile.PL options: MP_APR_CONFIG => /usr/bin/apr-config MP_APR_LIB => aprext MP_APXS => /usr/bin/apxs MP_CCOPTS => -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wall MP_COMPAT_1X => 1 MP_GENERATE_XS => 1 MP_LIBNAME => mod_perl MP_TRACE => 0 MP_USE_DSO => 1 MP_USE_STATIC => 0 *** The httpd binary was not found *** (apr|apu)-config linking info (apr|apu)-config scripts were not found *** /usr/bin/perl -V Summary of my perl5 (revision 5 version 20 subversion 2) configuration: Platform: osname=linux, osvers=3.2.0-58-generic, archname=x86_64-linux-gnu-thread-multi uname='linux kissel 3.2.0-58-generic #88-ubuntu smp tue dec 3 17:37:58 utc 2013 x86_64 x86_64 x86_64 gnulinux ' config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Dldflags= -Wl,-Bsymbolic-functions -Wl,-z,relro -Dlddlflags=-shared -Wl,-Bsymbolic-functions -Wl,-z,relro -Dcccdlflags=-fPIC -Darchname=x86_64-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.20 -Darchlib=/usr/lib/x86_64-linux-gnu/perl/5.20 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/x86_64-linux-gnu/perl5/5.20 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.20.2 -Dsitearch=/usr/local/lib/x86_64-linux-gnu/perl/5.20.2 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Duse64bitint -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -Ui_libutil -Uversiononly -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.20.2 -des' hint=recommended, useposix=true, d_sigaction=define useithreads=define, usemultiplicity=define use64bitint=define, use64bitall=define, uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', optimize='-O2 -g', cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include' ccversion='', gccversion='4.9.2', gccosandvers='' intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16 ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8 alignbytes=8, prototype=define Linker and Libraries: ld='cc', ldflags =' -fstack-protector -L/usr/local/lib' libpth=/usr/local/lib /usr/lib/gcc/x86_64-linux-gnu/4.9/include-fixed /usr/include/x86_64-linux-gnu /usr/lib /lib/x86_64-linux-gnu /lib/../lib /usr/lib/x86_64-linux-gnu /usr/lib/../lib /lib libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt perllibs=-ldl -lm -lpthread -lc -lcrypt libc=libc-2.19.so, so=so, useshrplib=true, libperl=libperl.so.5.20 gnulibc_version='2.19' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E' cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib -fstack-protector' Characteristics of this binary (from libperl): Compile-time options: HAS_TIMES MULTIPLICITY PERLIO_LAYERS PERL_DONT_CREATE_GVSV PERL_HASH_FUNC_ONE_AT_A_TIME_HARD PERL_IMPLICIT_CONTEXT PERL_MALLOC_WRAP PERL_NEW_COPY_ON_WRITE PERL_PRESERVE_IVUV USE_64_BIT_ALL USE_64_BIT_INT USE_ITHREADS USE_LARGE_FILES USE_LOCALE USE_LOCALE_COLLATE USE_LOCALE_CTYPE USE_LOCALE_NUMERIC USE_PERLIO USE_PERL_ATOF USE_REENTRANT_API Locally applied patches: DEBPKG:debian/cpan_definstalldirs - Provide a sensible INSTALLDIRS default for modules installed from CPAN. DEBPKG:debian/db_file_ver - http://bugs.debian.org/340047 Remove overly restrictive DB_File version check. DEBPKG:debian/doc_info - Replace generic man(1) instructions with Debian-specific information. DEBPKG:debian/enc2xs_inc - http://bugs.debian.org/290336 Tweak enc2xs to follow symlinks and ignore missing @INC directories. DEBPKG:debian/errno_ver - http://bugs.debian.org/343351 Remove Errno version check due to upgrade problems with long-running processes. DEBPKG:debian/libperl_embed_doc - http://bugs.debian.org/186778 Note that libperl-dev package is required for embedded linking DEBPKG:fixes/respect_umask - Respect umask during installation DEBPKG:debian/writable_site_dirs - Set umask approproately for site install directories DEBPKG:debian/extutils_set_libperl_path - EU:MM: set location of libperl.a under /usr/lib DEBPKG:debian/no_packlist_perllocal - Don't install .packlist or perllocal.pod for perl or vendor DEBPKG:debian/prefix_changes - Fiddle with *PREFIX and variables written to the makefile DEBPKG:debian/fakeroot - Postpone LD_LIBRARY_PATH evaluation to the binary targets. DEBPKG:debian/instmodsh_doc - Debian policy doesn't install .packlist files for core or vendor. DEBPKG:debian/ld_run_path - Remove standard libs from LD_RUN_PATH as per Debian policy. DEBPKG:debian/libnet_config_path - Set location of libnet.cfg to /etc/perl/Net as /usr may not be writable. DEBPKG:debian/mod_paths - Tweak @INC ordering for Debian DEBPKG:debian/module_build_man_extensions - http://bugs.debian.org/479460 Adjust Module::Build manual page extensions for the Debian Perl policy DEBPKG:debian/prune_libs - http://bugs.debian.org/128355 Prune the list of libraries wanted to what we actually need. DEBPKG:fixes/net_smtp_docs - [rt.cpan.org #36038] http://bugs.debian.org/100195 Document the Net::SMTP 'Port' option DEBPKG:debian/perlivp - http://bugs.debian.org/510895 Make perlivp skip include directories in /usr/local DEBPKG:debian/deprecate-with-apt - http://bugs.debian.org/747628 Point users to Debian packages of deprecated core modules DEBPKG:debian/squelch-locale-warnings - http://bugs.debian.org/508764 Squelch locale warnings in Debian package maintainer scripts DEBPKG:debian/skip-upstream-git-tests - Skip tests specific to the upstream Git repository DEBPKG:debian/patchlevel - http://bugs.debian.org/567489 List packaged patches for 5.20.2-2 in patchlevel.h DEBPKG:debian/skip-kfreebsd-crash - http://bugs.debian.org/628493 [perl #96272] Skip a crashing test case in t/op/threads.t on GNU/kFreeBSD DEBPKG:fixes/document_makemaker_ccflags - http://bugs.debian.org/628522 [rt.cpan.org #68613] Document that CCFLAGS should include $Config{ccflags} DEBPKG:debian/find_html2text - http://bugs.debian.org/640479 Configure CPAN::Distribution with correct name of html2text DEBPKG:debian/perl5db-x-terminal-emulator.patch - http://bugs.debian.org/668490 Invoke x-terminal-emulator rather than xterm in perl5db.pl DEBPKG:debian/cpan-missing-site-dirs - http://bugs.debian.org/688842 Fix CPAN::FirstTime defaults with nonexisting site dirs if a parent is writable DEBPKG:fixes/memoize_storable_nstore - [rt.cpan.org #77790] http://bugs.debian.org/587650 Memoize::Storable: respect 'nstore' option not respected DEBPKG:debian/regen-skip - Skip a regeneration check in unrelated git repositories DEBPKG:fixes/regcomp-mips-optim - [perl #122817] http://bugs.debian.org/754054 Downgrade the optimization of regcomp.c on mips and mipsel due to a gcc-4.9 bug DEBPKG:debian/makemaker-pasthru - http://bugs.debian.org/758471 Pass LD settings through to subdirectories DEBPKG:fixes/perldoc-less-R - [rt.cpan.org #98636] http://bugs.debian.org/758689 Tell the 'less' pager to allow terminal escape sequences DEBPKG:fixes/pod_man_reproducible_date - http://bugs.debian.org/759405 Support POD_MAN_DATE in Pod::Man for the left-hand footer DEBPKG:fixes/io_uncompress_gunzip_inmemory - http://bugs.debian.org/747363 [rt.cpan.org #95494] Fix gunzip to in-memory file handle DEBPKG:fixes/socket_test_recv_fix - http://bugs.debian.org/758718 [perl #122657] Compare recv return value to peername in socket test DEBPKG:fixes/hurd_socket_recv_todo - http://bugs.debian.org/758718 [perl #122657] TODO checking the result of recv() on hurd DEBPKG:fixes/regexp-performance - [0fa70a0] http://bugs.debian.org/777556 [perl #123743] simpify and speed up /.*.../ handling Built under linux Compiled at Mar 3 2015 11:44:27 %ENV: PERL_LWP_USE_HTTP_10="1" @INC: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.20.2 /usr/local/share/perl/5.20.2 /usr/lib/x86_64-linux-gnu/perl5/5.20 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.20 /usr/share/perl/5.20 /usr/local/lib/site_perl . 3. This is the core dump trace: (if you get a core dump): #0 0x00007f455212ce70 in ?? () #1 0x00007f4557301a04 in Perl_newBINOP () from /tmp/apport_sandbox_l8WbDl/usr/lib/x86_64-linux-gnu/libperl.so.5.20 #2 0x00007f4557342cf1 in Perl_yyparse () from /tmp/apport_sandbox_l8WbDl/usr/lib/x86_64-linux-gnu/libperl.so.5.20 #3 0x00007f45573c5342 in ?? () from /tmp/apport_sandbox_l8WbDl/usr/lib/x86_64-linux-gnu/libperl.so.5.20 #4 0x00007f45573d0fa0 in Perl_pp_require () from /tmp/apport_sandbox_l8WbDl/usr/lib/x86_64-linux-gnu/libperl.so.5.20 #5 0x00007f455738bbb6 in Perl_runops_standard () from /tmp/apport_sandbox_l8WbDl/usr/lib/x86_64-linux-gnu/libperl.so.5.20 #6 0x00007f45573153a1 in Perl_eval_sv () from /tmp/apport_sandbox_l8WbDl/usr/lib/x86_64-linux-gnu/libperl.so.5.20 #7 0x00007f455769fa04 in modperl_require_module () from /tmp/apport_sandbox_l8WbDl/usr/lib/apache2/modules/mod_perl.so #8 0x00007f45576963e7 in ?? () from /tmp/apport_sandbox_l8WbDl/usr/lib/apache2/modules/mod_perl.so #9 0x00007f45573c20a9 in Perl_leave_scope () from /tmp/apport_sandbox_l8WbDl/usr/lib/x86_64-linux-gnu/libperl.so.5.20 #10 0x00007f455731b68a in perl_parse () from /tmp/apport_sandbox_l8WbDl/usr/lib/x86_64-linux-gnu/libperl.so.5.20 #11 0x00007f4557696ab3 in modperl_startup () from /tmp/apport_sandbox_l8WbDl/usr/lib/apache2/modules/mod_perl.so #12 0x00007f4557696a43 in modperl_startup () from /tmp/apport_sandbox_l8WbDl/usr/lib/apache2/modules/mod_perl.so #13 0x00007f4557696e76 in modperl_init () from /tmp/apport_sandbox_l8WbDl/usr/lib/apache2/modules/mod_perl.so #14 0x00007f4557696feb in modperl_hook_init () from /tmp/apport_sandbox_l8WbDl/usr/lib/apache2/modules/mod_perl.so #15 0x00007f455769a6f6 in modperl_cmd_perldo () from /tmp/apport_sandbox_l8WbDl/usr/lib/apache2/modules/mod_perl.so #16 0x00007f455b2cdd5e in invoke_cmd (cmd=0x7f45578c1570, parms=0x7fff96bf48d0, mconfig=0x7f455b20ac90, args=0x7f455b1d74d8 "$[\n") at config.c:879 #17 0x00007f455b2d045f in ap_walk_config_sub (section_vector=<optimized out>, parms=<optimized out>, current=<optimized out>) at config.c:1309 #18 ap_walk_config (current=0x7f455b1d74e0, parms=0x7fff96bf48d0, section_vector=0x7f455b2334e8) at config.c:1342 #19 0x00007f455b2d176d in ap_process_config_tree (s=0x7f455c2ea940, conftree=0x25, p=0x7f455b264028, ptemp=0x7f4557681c80 <PL_ppaddr>) at config.c:2059 #20 0x00007f455b2ae143 in main (argc=2, argv=0x7fff96bf4b28) at main.c:739 This report was generated by -e on Thu May 21 18:07:21 2015 GMT. -------------8<---------- End Bug Report --------------8<----------