Can't build from source with gcc-10 (Version: 1.12.0)

[nmiceli-simtlix]

Issue Description

Can't build with latest release

Steps to Reproduce

git clone https://github.com/xrplf/rippled
git checkout 89780c8e4fd4d140fcb912cf2d0c01c1b260539e
conan export external/snappy snappy/1.1.10@
conan export external/soci soci/4.0.3@
mkdir .build && cd .build
conan install .. --output-folder . --build missing --settings build_type=Release
cmake -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake -DCMAKE_BUILD_TYPE=Release ..
cmake --build . -- --quiet

Expected Result

a built rippled binary

Actual Result

#13 441.1 [ 10%] Building CXX object CMakeFiles/xrpl_core.dir/src/ripple/protocol/impl/SField.cpp.o
#13 442.0 [ 10%] Building CXX object CMakeFiles/xrpl_core.dir/src/ripple/protocol/impl/SOTemplate.cpp.o
#13 443.0 [ 10%] Building CXX object CMakeFiles/xrpl_core.dir/src/ripple/protocol/impl/STAccount.cpp.o
#13 445.7 [ 10%] Building CXX object CMakeFiles/xrpl_core.dir/src/ripple/protocol/impl/STAmount.cpp.o
#13 449.2 /build/ripple/binary/src/ripple/protocol/impl/STAmount.cpp: In lambda function:
#13 449.2 /build/ripple/binary/src/ripple/protocol/impl/STAmount.cpp:1577:15: error: expected nested-name-specifier before 'enum'
#13 449.2  1577 |         using enum Number::rounding_mode;
#13 449.2       |               ^~~~
#13 449.2 /build/ripple/binary/src/ripple/protocol/impl/STAmount.cpp:1579:40: error: 'upward' was not declared in this scope
#13 449.2  1579 |             roundUp ^ resultNegative ? upward : downward);
#13 449.2       |                                        ^~~~~~
#13 449.2 /build/ripple/binary/src/ripple/protocol/impl/STAmount.cpp:1579:49: error: 'downward' was not declared in this scope
#13 449.2  1579 |             roundUp ^ resultNegative ? upward : downward);
#13 449.2       |                                                 ^~~~~~~~
#13 449.3 /build/ripple/binary/src/ripple/protocol/impl/STAmount.cpp: In instantiation of 'ripple::STAmount ripple::divRoundImpl(const ripple::STAmount&, const ripple::STAmount&, const ripple::Issue&, bool) [with MightSaveRound = ripple::{anonymous}::DontAffectNumberRoundMode]':
#13 449.3 /build/ripple/binary/src/ripple/protocol/impl/STAmount.cpp:1609:76:   required from here
#13 449.3 /build/ripple/binary/src/ripple/protocol/impl/STAmount.cpp:1578:30: warning: unused variable 'savedRound' [-Wunused-variable]
#13 449.3  1578 |         MightSaveRound const savedRound(
#13 449.3       |                              ^~~~~~~~~~
#13 450.1 make[2]: *** [CMakeFiles/xrpl_core.dir/build.make:863: CMakeFiles/xrpl_core.dir/src/ripple/protocol/impl/STAmount.cpp.o] Error 1
#13 450.1 make[1]: *** [CMakeFiles/Makefile2:120: CMakeFiles/xrpl_core.dir/all] Error 2
#13 450.1 make: *** [Makefile:130: all] Error 2

Environment

Ubuntu 20.04
CONAN_RELEASE_VERSION=1.59.0

[ckeshava]

Hello, thanks for bringing this issue to our attention.

Can you confirm that you adhere to the minimum compiler versions as listed here:

This issue has been observed with older versions of cpp compilers, because they don't allow for enum classes.

[nmiceli-simtlix]

I believe I do. I had no problems when compiling previous versions.

python3.8                              3.8.10-0ubuntu1~20.04.8
cmake                                  3.16.3-1ubuntu1.20.04.1
cpp-10                                 10.5.0-1ubuntu1~20.04
g++-10                                 10.5.0-1ubuntu1~20.04
gcc-10                                 10.5.0-1ubuntu1~20.04
conan                                  1.59.0

Should I try something different with any of these?

[legleux]

I believe our minimum requirements should be updated to require GCC 11 for using enum.
https://gcc.gnu.org/projects/cxx-status.html

[nmiceli-simtlix]

Yes. That was the problem.
Updating cpp, g++ and gcc to v11 fixed my issue.
Those requirements should be updated.
Thanks!

[ckeshava]

thnks for the insight @legleux I have opened a PR to fix this discrepancy 👍

[intelliot]

Looks like using enum was first introduced with 724a301 (Jun 22, 2023)