Support `--emit-tsd` in Docker container by default

[merceyz]

The emscripten/emsdk:3.1.57 container doesn't contain tsc so the --emit-tsd flag doesn't work by default.

It would be nice if the Docker container could contain tsc by default.

Reproduction:

touch test.c && docker run --rm -it -v "$(pwd):/src" emscripten/emsdk:3.1.57 emcc -o ./build.js --emit-tsd ./build.d.ts -v ./test.c

 /emsdk/upstream/bin/clang -target wasm32-unknown-emscripten -fignore-exceptions -fvisibility=default -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --sysroot=/emsdk/upstream/emscripten/cache/sysroot -DEMSCRIPTEN -Werror=implicit-function-declaration -Xclang -iwithsysroot/include/fakesdl -Xclang -iwithsysroot/include/compat -v ./test.c -c -o /tmp/emscripten_temp_dmia875v/test_0.o
clang version 19.0.0git (https:/github.com/llvm/llvm-project ccdebbae4d77d3efc236af92c22941de5d437e01)
Target: wasm32-unknown-emscripten
Thread model: posix
InstalledDir: /emsdk/upstream/bin
 (in-process)
 "/emsdk/upstream/bin/clang-19" -cc1 -triple wasm32-unknown-emscripten -emit-obj -mrelax-all -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name test.c -mrelocation-model static -mframe-pointer=none -ffp-contract=on -fno-rounding-math -mconstructor-aliases -target-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/src -v -fcoverage-compilation-dir=/src -resource-dir /emsdk/upstream/lib/clang/19 -D EMSCRIPTEN -isysroot /emsdk/upstream/emscripten/cache/sysroot -internal-isystem /emsdk/upstream/lib/clang/19/include -internal-isystem /emsdk/upstream/emscripten/cache/sysroot/include/wasm32-emscripten -internal-isystem /emsdk/upstream/emscripten/cache/sysroot/include -Werror=implicit-function-declaration -ferror-limit 19 -fvisibility=default -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fignore-exceptions -fcolor-diagnostics -iwithsysroot/include/fakesdl -iwithsysroot/include/compat -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr -o /tmp/emscripten_temp_dmia875v/test_0.o -x c ./test.c
clang -cc1 version 19.0.0git based upon LLVM 19.0.0git default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/emsdk/upstream/emscripten/cache/sysroot/include/wasm32-emscripten"
#include "..." search starts here:
#include <...> search starts here:
 /emsdk/upstream/emscripten/cache/sysroot/include/fakesdl
 /emsdk/upstream/emscripten/cache/sysroot/include/compat
 /emsdk/upstream/lib/clang/19/include
 /emsdk/upstream/emscripten/cache/sysroot/include
End of search list.
 /emsdk/upstream/bin/clang --version
cache:INFO: generating system asset: symbol_lists/01e1e9a4c0bd6ca93092d8b7f3eedeb510e4cfc6.json... (this will be cached in "/emsdk/upstream/emscripten/cache/symbol_lists/01e1e9a4c0bd6ca93092d8b7f3eedeb510e4cfc6.json" for subsequent builds)
 /emsdk/node/16.20.0_64bit/bin/node /emsdk/upstream/emscripten/src/compiler.mjs /tmp/tmp4p3ssnds.json --symbols-only
cache:INFO:  - ok
 /emsdk/upstream/bin/wasm-ld -o ./build.wasm -L/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten /tmp/emscripten_temp_dmia875v/test_0.o -lGL-getprocaddr -lal -lhtml5 -lstubs-debug -lnoexit -lc-debug -ldlmalloc -lcompiler_rt -lc++-noexcept -lc++abi-debug-noexcept -lsockets -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr /tmp/tmpibd69osblibemscripten_js_symbols.so --strip-debug --export=emscripten_stack_get_end --export=emscripten_stack_get_free --export=emscripten_stack_get_base --export=emscripten_stack_get_current --export=emscripten_stack_init --export=_emscripten_stack_alloc --export=__get_temp_ret --export=__set_temp_ret --export=__wasm_call_ctors --export=_emscripten_stack_restore --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-if-defined=__start_em_lib_deps --export-if-defined=__stop_em_lib_deps --export-if-defined=__start_em_js --export-if-defined=__stop_em_js --export-if-defined=main --export-if-defined=__main_argc_argv --export-if-defined=fflush --export-table -z stack-size=65536 --no-growable-memory --initial-heap=16777216 --no-entry --stack-first --table-base=1
 /emsdk/upstream/bin/llvm-objcopy ./build.wasm ./build.wasm --remove-section=.debug* --remove-section=producers
 /emsdk/upstream/bin/wasm-emscripten-finalize --dyncalls-i64 --pass-arg=legalize-js-interface-exported-helpers ./build.wasm -o ./build.wasm --detect-features
 /emsdk/node/16.20.0_64bit/bin/node /emsdk/upstream/emscripten/src/compiler.mjs /tmp/tmp0xih23ki.json
emcc: error: tsc was not found! Please run "npm install" in Emscripten root directory to set up npm dependencies

[sbc100]

Sounds reasonable. What is the best why to install tsc do you think? Would you have time to set a PR the Dockerfile to ensure it is installed?

[merceyz]

I've opened https://github.com/emscripten-core/emsdk/pull/1371 which installs the npm dependencies of emscripten during docker build.