Bug #20045
open
`TestDir#test_home` fails on i686
Description
This is followup to #19147. Testing on Fedora 38 and Fedora Rawhide, we are facing this test failure:
$ tar xf build/SOURCES/ruby-3.2.2.tar.xz
$ cd ruby-3.2.2/
$ ./configure && make
... snip ...
---
Configuration summary for ruby version 3.2.2
* Installation prefix: /usr/local
* exec prefix: ${prefix}
* arch: i686-linux
* site arch: ${arch}
* RUBY_BASE_NAME: ruby
* ruby lib prefix: ${libdir}/${RUBY_BASE_NAME}
* site libraries path: ${rubylibprefix}/${sitearch}
* vendor path: ${rubylibprefix}/vendor_ruby
* target OS: linux
* compiler: gcc
* with thread: pthread
* with coroutine: x86
* enable shared libs: no
* dynamic library ext: so
* CFLAGS: ${optflags} ${debugflags} ${warnflags}
* LDFLAGS: -L. -fstack-protector-strong -rdynamic -Wl,-export-dynamic
* DLDFLAGS: -Wl,--compress-debug-sections=zlib
* optflags: -O3 -fno-fast-math
* debugflags: -ggdb3
* warnflags: -Wall -Wextra -Wdeprecated-declarations -Wdiv-by-zero -Wduplicated-cond -Wimplicit-function-declaration -Wimplicit-int -Wmisleading-indentation -Wpointer-arith -Wwrite-strings -Wold-style-definition \
-Wimplicit-fallthrough=0 -Wmissing-noreturn -Wno-cast-function-type -Wno-constant-logical-operand -Wno-long-long -Wno-missing-field-initializers -Wno-overlength-strings -Wno-packed-bitfield-compat \
-Wno-parentheses-equality -Wno-self-assign -Wno-tautological-compare -Wno-unused-parameter -Wno-unused-value -Wsuggest-attribute=format -Wsuggest-attribute=noreturn -Wunused-variable -Wundef
* strip command: strip -S -x
* install doc: rdoc
* MJIT support: yes
* YJIT support: no
* man page type: doc
---
... snip ...
$ LANG=C make test-all 'TESTS=-v -n /TestDir#test_home/'
config.status: creating ruby-runner.h
making mjit_build_dir.so
generating i686-linux-fake.rb
i686-linux-fake.rb updated
Run options:
--seed=10517
"--ruby=./miniruby -I./lib -I. -I.ext/common ./tool/runruby.rb --extout=.ext -- --disable-gems"
--excludes-dir=./test/excludes
--name=!/memory_leak/
-v
-n
/TestDir#test_home/
# Running tests:
[1/0] TestDir#test_home = 0.00 s
1) Error:
TestDir#test_home:
RuntimeError: can't set length of shared string
/builddir/ruby-3.2.2/test/ruby/test_dir.rb:557:in `expand_path'
/builddir/ruby-3.2.2/test/ruby/test_dir.rb:557:in `block in test_home'
Finished tests in 4.164691s, 0.2401 tests/s, 1.6808 assertions/s.
1 tests, 7 assertions, 0 failures, 1 errors, 0 skips
ruby -v: ruby 3.2.2 (2023-03-30 revision e51014f9c0) [i686-linux]
make: *** [uncommon.mk:855: yes-test-all] Error 1
Please note that having the C locale is essential. The test passes just fine with e.g. C.UTF-8 locale.
We were able to reduce the test case to the following:
$ whoami
mockbuild
$ echo 'File.expand_path("~mockbuild")' > test.rb
$ LANG=C RUBYLIB=/builddir/ruby-3.2.2/.ext/i686-linux LD_LIBRARY_PATH=. ./ruby --disable-gems test.rb
test.rb:1:in `expand_path': can't set length of shared string (RuntimeError)
from test.rb:1:in `<main>'
As I said earlier, the LANG=C is essential as well as the RUBYLIB=/builddir/ruby-3.2.2/.ext/i386-linux. Adding the path to RUBYLIB enables Ruby to load the following libraries:
/builddir/ruby-3.2.2/.ext/i686-linux/enc/encdb.so
/builddir/ruby-3.2.2/.ext/i686-linux/enc/trans/transdb.so
And that makes the difference. Also, the File.expand_path("~mockbuild") must be in some file, replacing this by -e 'File.expand_path("~mockbuild")' does not reproduce the issue.
We also believe that this was introduced by https://github.com/ruby/ruby/pull/6699, specifically by git|5246f4027ec574e77809845e1b1f7822cc2a5cef and fixed in master by git|b4571097df4a6bd848f1195026d82a92f3a7f9d8.
Unfortunately, we were not able to discover what is the mechanism behind this, why this depends on locale, why the test must be in file, why the string is shared etc. But I hope we have provided enough details for someone else more knowledgeable.
Some background for this issue is also available here:
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