Building boost to web assembly fails about b2

[Kojoley]

Error: ambiguity found when searching for best transformation
Trying to produce type 'SEARCHED_LIB' from: 
Generators that succeeded:
 -  searched-lib-generator
 -  emscripten.searched-lib-generator
First generator produced: 
 -  { %.no-action-z.SEARCHED_LIB }
Second generator produced: 
 -  { %.no-action-z.SEARCHED_LIB }

The issue can be fixed by patching the b2 jamfile src/tools/emscripten.jam that boost 1.83.0 depends on as follows....

This has been fixed in #225 and emscripten support overhaul happened in #310

error: No best alternative for libs/context/build/asm_sources with sysv 32 off mach-o <boost.locale.iconv.lib>libc <boost.locale.iconv>on <boost.locale.icu>off off fcontext off on 32 off on off off off static on off MACOSX on on off off 3.11 abi address-model architecture binary-format toolset on on shared native off darwin <testing.execute>on pthread multi toolset-emscripten:version3.1.44 emscripten debug off hidden off on

It's not a b2 issue. AFAIK emscripten is not supported by Boost.Context, file an issue there.