Seemingly random compilation failures

[richardlau]

From @tniessen via https://openjs-foundation.slack.com/archives/C03BJP63CH0/p1747507311133849

Has anyone else seen some unexpected compilation failures during Jenkins CI runs? For example, this run failed with C++ compiler errors even though the PR being tested does not touch C++ at all, and I am pretty sure I saw some similar errors over the last few days: https://ci.nodejs.org/job/node-test-commit-linux-containered/50707/

e.g. https://ci.nodejs.org/job/node-test-commit-linux-containered/50707/nodes=ubuntu2204_sharedlibs_shared_x64/console

19:19:39 In file included from ../deps/ada/ada.cpp:3:
19:19:39 ../deps/ada/ada.h: In member function 'constexpr std::string_view ada::url::get_pathname() const':
19:19:39 ../deps/ada/ada.h:6621:10: error: call to non-'constexpr' function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::operator std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__sv_type() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__sv_type = std::basic_string_view<char>]'
19:19:39  6621 |   return path;
19:19:39       |          ^~~~
19:19:39 In file included from /usr/include/c++/11/string:55,
19:19:39                  from ../deps/ada/ada.h:20,
19:19:39                  from ../deps/ada/ada.cpp:3:
19:19:39 /usr/include/c++/11/bits/basic_string.h:806:7: note: 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::operator std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__sv_type() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__sv_type = std::basic_string_view<char>]' declared here
19:19:39   806 |       operator __sv_type() const noexcept
19:19:39       |       ^~~~~~~~
...

[richardlau]

From the full console log it looks like something has gone wrong with the compiler selector -- it is supposed to be switching to gcc 12 for main but instead the default compiler (gcc 11) is being used:
https://ci.nodejs.org/job/node-test-commit-linux-containered/50707/nodes=ubuntu2204_sharedlibs_shared_x64/consoleFull

19:19:21 + curl -sLO https://raw.githubusercontent.com/nodejs/build/main/jenkins/scripts/select-compiler.sh
19:19:21 + . ./select-compiler.sh
19:19:21 ++ which ccache
19:19:21 + '[' '!' -z /usr/bin/ccache ']'
19:19:21 ++ which
19:19:21 + '[' '!' -z '' ']'
19:19:21 ++ which gcc
19:19:21 + '[' '!' -z /usr/lib/ccache/gcc ']'
19:19:21 + export 'CC=ccache gcc'
19:19:21 + CC='ccache gcc'
19:19:21 ++ which
19:19:21 + '[' '!' -z '' ']'
19:19:21 ++ which g++
19:19:21 + '[' '!' -z /usr/lib/ccache/g++ ']'
19:19:21 + export 'CXX=ccache g++'
19:19:21 + CXX='ccache g++'
19:19:21 + '[' false = true ']'
19:19:21 + FLAKY_TESTS_MODE=run
19:19:21 + test true = true
19:19:21 + FLAKY_TESTS_MODE=dontcare
19:19:21 + echo FLAKY_TESTS_MODE=dontcare
19:19:21 FLAKY_TESTS_MODE=dontcare
19:19:21 + '[' -z x ']'
19:19:21 + NODE_TEST_DIR=/home/iojs/node-tmp
19:19:21 + FLAKY_TESTS=dontcare
19:19:23 + CONFIG_FLAGS=' --shared'
19:19:23 + make run-ci -j 4
19:19:23 python3 ./configure --verbose  --shared
19:19:23 Node.js configure: Found Python 3.10.12...
19:19:23 Detected C++ compiler (CXX=ccache g++) version: 11.4.0
19:19:23 WARNING: C++ compiler (CXX=ccache g++, 11.4.0) too old, need g++ 12.2.0 or clang++ 8.0.0
19:19:23 Detected C compiler (CC=ccache gcc) version: 11.4.0

select-compiler.sh last changed five months ago, so this is not an obvious regression. Also only some builds are failing, and not all of the node-test-commit-linux-containered jobs for the same PR.

I think the most plausible explanation is that

curl -sLO https://raw.githubusercontent.com/nodejs/build/main/jenkins/scripts/select-compiler.sh

has gone awry, possibly resulting in an empty script (see nodejs/node#58381 for what looks like a similar situation where using curl to fetch a raw GitHub URL also seemingly resulted in empty results).

[legendecas]

We chould potentially add --fail to curl commands (or -f for short, and with -S to print errors in case for debugging), making the error louder, rather than returning an empty result.