Issue with re2 package

[Mark Davies <mark%ecs.vuw.ac.nz@localhost>]

I'm trying to get qt6-qtwebengine to use the pkgsrc re2 package rather 
than using its own copy, but if I do that I get so far through the build 
and get this error:

/usr/bin/ld: obj/third_party/blink/common/common/common_jumbo_7.o: in 
function `blink::ParseAdSizeString(std::basic_string_view<char, 
std::char_traits<char> >)':
common_jumbo_7.cc:(.text._ZN5blink17ParseAdSizeStringESt17basic_string_viewIcSt11char_traitsIcEE+0x10c): 
undefined reference to 
`re2::RE2::FullMatchN(std::basic_string_view<char, 
std::char_traits<char> >, re2::RE2 const&, re2::RE2::Arg const* const*, 
int)'
/usr/bin/ld: 
obj/components/shared_highlighting/core/common/common/disabled_sites.o: 
in function `shared_highlighting::ShouldOfferLinkToText(GURL const&)':
disabled_sites.cc:(.text._ZN19shared_highlighting21ShouldOfferLinkToTextERK4GURL+0xf1): 
undefined reference to 
`re2::RE2::FullMatchN(std::basic_string_view<char, 
std::char_traits<char> >, re2::RE2 const&, re2::RE2::Arg const* const*, 
int)'
collect2: error: ld returned 1 exit status

but with the internal copy it links fine.

And indeed the function in the library differs:

# nm -D -C /usr/pkg/lib/libre2.so | grep FullMatchN 
                 000000000003c6f2 T 
re2::RE2::FullMatchN(absl::lts_20250127::string_view, re2::RE2 const&, 
re2::RE2::Arg const* const*, int)

# nm -C 
work.x86_64/qtwebengine-everywhere-src-6.8.2/src/core/Release/x86_64/obj/third_party/re2/libbundled_re2.a 
| grep FullMatchN
0000000000000000 T re2::RE2::FullMatchN(std::basic_string_view<char, 
std::char_traits<char> >, re2::RE2 const&, re2::RE2::Arg const* const*, int)


And if I look at our ArchLinux machines I get a similar difference 
between the pkgsrc package and the ArchLinux package:

% nm -D -C /usr/pkg/lib/libre2.so | grep FullMatchN
0000000000053020 T re2::RE2::FullMatchN(absl::lts_20240722::string_view, 
re2::RE2 const&, re2::RE2::Arg const* const*, int)

% nm -D -C /usr/lib/libre2.so | grep FullMatchN
000000000002b600 T re2::RE2::FullMatchN(std::basic_string_view<char, 
std::char_traits<char> >, re2::RE2 const&, re2::RE2::Arg const* const*, int)


Anybody got any idea whats going on?

cheers
mark