Error building seastar on Fedora 35

[talawahtech]

Attempts to build seastar master (0c86ae0feda9b1052f0f019fad0d0b1a0ba098c1) by following the steps outlined in the README fail on Fedora 35. Note that the build completes successfully without issue on Fedora 34.

Server: AWS EC2 instance (c5n.4xlarge) AMI Version: Fedora-Cloud-Base-35-1.2.x86_64-hvm-us-east-2-gp2-0 (ami-0133ad8c5d900ddef) g++ version: 11.2.1 20210728 (Red Hat 11.2.1-1)

Steps to reproduce:

1. Launch Instance/AMI
2. sudo yum install git
3. git clone https://github.com/scylladb/seastar/ && cd seastar
4. sudo ./install-dependencies.sh
5. ./configure.py --mode=release --c++-dialect gnu++20
6. ninja -C build/release

Error:

[206/304] Building CXX object tests/unit/CMakeFiles/test_unit_log_buf.dir/log_buf_test.cc.o
FAILED: tests/unit/CMakeFiles/test_unit_log_buf.dir/log_buf_test.cc.o
/usr/bin/g++ -DBOOST_TEST_DYN_LINK -DFMT_LOCALE -DFMT_SHARED -DSEASTAR_API_LEVEL=6 -DSEASTAR_DEFERRED_ACTION_REQUIRE_NOEXCEPT -DSEASTAR_HAS_MEMBARRIER -DSEASTAR_HAVE_ASAN_FIBER_SUPPORT -DSEASTAR_HAVE_HWLOC -DSEASTAR_HAVE_LZ4_COMPRESS_DEFAULT -DSEASTAR_HAVE_NUMA -DSEASTAR_SCHEDULING_GROUPS_COUNT=16 -DSEASTAR_TESTING_MAIN -I/home/fedora/seastar/tests/unit -I/home/fedora/seastar/src -I/home/fedora/seastar/include -I/home/fedora/seastar/build/release/gen/include -O2 -g -DNDEBUG -std=gnu++20 -U_FORTIFY_SOURCE -Wno-maybe-uninitialized -DSEASTAR_SSTRING -Wno-error=unused-result -fvisibility=hidden -UNDEBUG -Wall -Werror -Wno-array-bounds -Wno-error=deprecated-declarations -gz -std=gnu++20 -MD -MT tests/unit/CMakeFiles/test_unit_log_buf.dir/log_buf_test.cc.o -MF tests/unit/CMakeFiles/test_unit_log_buf.dir/log_buf_test.cc.o.d -o tests/unit/CMakeFiles/test_unit_log_buf.dir/log_buf_test.cc.o -c /home/fedora/seastar/tests/unit/log_buf_test.cc
/home/fedora/seastar/tests/unit/log_buf_test.cc: In member function ‘virtual seastar::future<> log_buf_insert_iterator_format_to::run_test_case()’:
/home/fedora/seastar/tests/unit/log_buf_test.cc:69:24:   in ‘constexpr’ expansion of ‘fmt::v8::basic_format_string<char, const long unsigned int&>(str)’
/usr/include/fmt/core.h:2835:51:   in ‘constexpr’ expansion of ‘((fmt::v8::basic_format_string<char, const long unsigned int&>*)this)->fmt::v8::basic_format_string<char, const long unsigned int&>::str_.fmt::v8::basic_string_view<char>::basic_string_view(((const char*)s))’
/usr/include/fmt/core.h:465:45:   in ‘constexpr’ expansion of ‘std::char_traits<char>::length(s)’
/usr/include/c++/11/bits/char_traits.h:369:52:   in ‘constexpr’ expansion of ‘__gnu_cxx::char_traits<char>::length(__s)’
/usr/include/c++/11/bits/char_traits.h:171:17:   in ‘constexpr’ expansion of ‘__gnu_cxx::char_traits<char>::eq((*(__p + ((sizetype)__i))), 0)’
/home/fedora/seastar/tests/unit/log_buf_test.cc:69:24: error: the value of ‘str’ is not usable in a constant expression
   69 |     it = fmt::format_to(it, str, size);
      |          ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
/home/fedora/seastar/tests/unit/log_buf_test.cc:58:10: note: ‘str’ was not declared ‘constexpr’
   58 |     char str[size + 1];
      |          ^~~
/home/fedora/seastar/tests/unit/log_buf_test.cc:76:24:   in ‘constexpr’ expansion of ‘fmt::v8::basic_format_string<char, const long unsigned int&>(str)’
/usr/include/fmt/core.h:2835:51:   in ‘constexpr’ expansion of ‘((fmt::v8::basic_format_string<char, const long unsigned int&>*)this)->fmt::v8::basic_format_string<char, const long unsigned int&>::str_.fmt::v8::basic_string_view<char>::basic_string_view(((const char*)s))’
/usr/include/fmt/core.h:465:45:   in ‘constexpr’ expansion of ‘std::char_traits<char>::length(s)’
/usr/include/c++/11/bits/char_traits.h:369:52:   in ‘constexpr’ expansion of ‘__gnu_cxx::char_traits<char>::length(__s)’
/usr/include/c++/11/bits/char_traits.h:171:17:   in ‘constexpr’ expansion of ‘__gnu_cxx::char_traits<char>::eq((*(__p + ((sizetype)__i))), 0)’
/home/fedora/seastar/tests/unit/log_buf_test.cc:76:24: error: the value of ‘str’ is not usable in a constant expression
   76 |     it = fmt::format_to(it, str, size);
      |          ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
/home/fedora/seastar/tests/unit/log_buf_test.cc:58:10: note: ‘str’ was not declared ‘constexpr’
   58 |     char str[size + 1];
      |          ^~~
[223/304] Building CXX object tests/unit/CMakeFiles/test_unit_rpc.dir/rpc_test.cc.o
ninja: build stopped: subcommand failed.

[psqli]

PR #983 fixes this

[psqli]

I'll send the patch to the mailing list ASAP.

[psqli]

Should be fixed by 9baead6e8842aded8ee84ecdfd2d5c4cef74acab

[psqli]

update: fmt-8.1.1 is now available on Fedora 35 https://bodhi.fedoraproject.org/updates/FEDORA-2022-71221357d9