[RELEASE] Downgrade version 2.6 to boost 1.83

[Bronek]

NOTE this is for release branch only

High Level Overview of Change

This fixes a problem where rippled could crash due a regression bug in boost 1.86

Context of Change

This is the result of an internal investigation into rippled crashes in testnet. We found the crashes to correspond to a documented regression in boost 1.86 and confirmed that this bug is not present in the older version of boost 1.83 , which was used before #5264 . We do not fully revert this PR since there is no need.

Type of Change

• Bug fix (non-breaking change which fixes an issue)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.8%. Comparing base (2df7dcf) to head (8d01f35).
⚠️ Report is 2 commits behind head on release.

Additional details and impacted files

@@            Coverage Diff            @@
##           release   #5759     +/-   ##
=========================================
- Coverage     78.8%   78.8%   -0.0%     
=========================================
  Files          814     814             
  Lines        71345   71310     -35     
  Branches      8357    8345     -12     
=========================================
- Hits         56234   56192     -42     
- Misses       15111   15118      +7     

Files with missing lines	Coverage Δ
src/libxrpl/protocol/BuildInfo.cpp	98.2% <ø> (ø)

... and 14 files with indirect coverage changes

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[Bronek]

Additional details:

Version 1.86 of boost introduced a regression bug in boost::beast demonstrated in boostorg/beast#2941 , where timeout on a network packet could cause termination of the process. The low level details of the bug are explained in boostorg/beast#2925 , and the fix is in boostorg/beast#2926 (also documented in https://github.com/boostorg/beast/blob/164db4bc57707b02550a53902cb1c138da99789f/CHANGELOG.md?plain=1#L32 )

This crash might produce a stacktrace from rippled with the following frames:

#2  0x0000000001963be6 in __gnu_cxx::__verbose_terminate_handler() [clone .cold] () at /usr/local/include/c++/12.5.0/bits/stl_construct.h:162
No symbol table info available.
#3  0x00000000046f5aba in __cxxabiv1::__terminate(void (*)()) ()
No symbol table info available.
#4  0x00000000046f5b25 in std::terminate() ()
No symbol table info available.
#5  0x00000000046f5c77 in __cxa_throw ()
No symbol table info available.
#6  0x0000000001859370 in boost::throw_exception<boost::asio::bad_executor> (e=<error reading variable: dwarf2_find_location_expression: Corrupted DWARF expression.>) at /root/.conan2/p/b/boost9dffe029038e8/p/include/boost/throw_exception.hpp:86
No locals.
#7  0x000000000185949f in boost::asio::executor::get_impl (this=<error reading variable: dwarf2_find_location_expression: Corrupted DWARF expression.>) at /root/.conan2/p/b/boost9dffe029038e8/p/include/boost/asio/executor.hpp:329
        ex = {<std::exception> = {<No data fields>}, <No data fields>}
.
.
.
#16 boost::asio::dispatch<boost::asio::detail::default_immediate_executor<boost::asio::executor, void, void>::type, boost::asio::append_t<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>::ops::transfer_op<false, boost::asio::const_buffers_1, boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::buffered_handshake_op<boost::asio::const_buffers_1>, boost::asio::detail::spawn_handler<boost::asio::executor, void (boost::system::error_code, unsigned long)> > > >, boost::system::error_code, int> >(boost::asio::detail::default_immediate_executor<boost::asio::executor, void, void>::type const&, boost::asio::append_t<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>::ops::transfer_op<false, boost::asio::const_buffers_1, boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::buffered_handshake_op<boost::asio::const_buffers_1>, boost::asio::detail::spawn_handler<boost::asio::executor, void (boost::system::error_code, unsigned long)> > > >, boost::system::error_code, int>&&, boost::asio::constraint<boost::asio::execution::is_executor<boost::asio::detail::default_immediate_executor<boost::asio::executor, void, void>::type>::value||boost::asio::is_executor<boost::asio::detail::default_immediate_executor<boost::asio::executor, void, void>::type>::value, int>::type) (ex=..., token=...) at /root/.conan2/p/b/boost9dffe029038e8/p/include/boost/asio/dispatch.hpp:156
No locals.
#17 0x00000000021bee9d in boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>::ops::transfer_op<false, boost::asio::const_buffers_1, boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::buffered_handshake_op<boost::asio::const_buffers_1>, boost::asio::detail::spawn_handler<boost::asio::executor, void (boost::system::error_code, unsigned long)> > > >::operator()(boost::system::error_code, unsigned long) (this=0x7f2c175afb00, ec=..., bytes_transferred=<optimized out>) at /usr/local/include/c++/12.5.0/tuple:199
        loc_333 = {file_ = 0x47d8e48 "/root/.conan2/p/b/boost9dffe029038e8/p/include/boost/beast/core/impl/basic_stream.hpp", function_ = 0x47d8ea0 "void boost::beast::basic_stream< <template-parameter-1-1>, <template-parameter-1-2>, <template-parameter-1-3> >::ops::transfer_op<isRead, Buffers, Handler>::operator()(boost::beast::error_code, std::s"..., line_ = 333, column_ = 17}
        amount = <error reading variable amount (dwarf2_find_location_expression: Corrupted DWARF expression.)>
        _coro_value = {value_ = @0x7f2c175afbc4, modified_ = true}

Frame 7 refers to an exception thrown (in noexcept context, hence process termination) in boost::asio when an event is processed without an executor. This is here https://github.com/boostorg/asio/blob/c28d453674dd2071fdc8cce5ffabcb54c910f466/include/boost/asio/executor.hpp#L329

The reason why there's no executor is explained in boostorg/beast#2925 and the frame 17 shows the buggy function being called https://github.com/boostorg/beast/blob/fee9be0be10c9c9a22ac1505a710d1d8ed5a3dfb/include/boost/beast/core/impl/basic_stream.hpp#L329 (packaged with BOOST_ASIO_CORO_YIELD which may defer execution, hence line 333 from BOOST_BEAST_ASSIGN_EC in the stacktrace above)

[xVet]

"packet timeout" so this is not triggered by specific transactions but potentially by random network activities?

[Bronek]

"packet timeout" so this is not triggered by specific transactions but potentially by random network activities?

Roughly, yes. There must be a pending TCP activity which is causing timeout, and then the next network operation will result in a crash. We did not spend much time looking for the reproduction of this bug, so I cannot tell you much more.