Thanks for reporting, this turns out ot be a recent regression in SINGLE_FILE. I bisected to
https://github.com/emscripten-core/emscripten/pull/25599 and posted there. - Alon On Thu, Oct 30, 2025 at 6:02 AM Thomas Grund <[email protected]> wrote: > Hello, > > The following example does > > - not work with current emcc 4.0.18 in Chrome. > > It > > - works with current emcc 4.0.18 in Firefox and it > - works with emcc 4.0.16 in Chrome. > > I use local files on Windows 11. > > Example index.html: > <!DOCTYPE html> > <html> > <head> > <script> > function compute() { > a=parseFloat(document.getElementById('a').value); > b=parseFloat(document.getElementById('b').value); > document.getElementById('c').innerText = Module.Sum(a, b); > } > </script> > <script src="Sum.js"></script> > </head> > <body> > <input id="a" type="number" onchange="compute()"> > <input id="b" type="number" onchange="compute()"> > <div id="c">Result</div> > </body> > </html> > > Example Sum.cpp: > #include <emscripten/bind.h> > > double Sum(double a, double b) { > return a+b; > } > > EMSCRIPTEN_BINDINGS(Module) { > emscripten::function("Sum", &Sum); > } > > Compile with: > emcc -o Sum.js Sum.cpp -sSINGLE_FILE --bind -sASSERTIONS > > Error in Chrome Console: > failed to asynchronously prepare wasm: CompileError: > WebAssembly.instantiate(): section was shorter than expected size (18371 > bytes expected, 207 decoded) @+219 > instantiateArrayBuffer @ Sum.js:634 > await in instantiateArrayBuffer > instantiateAsync @ Sum.js:645 > createWasm @ Sum.js:713 > (anonymous) @ Sum.js:2761Understand this error > Sum.js:275 Uncaught (in promise) TypeError: filename.startsWith is not a > function > isFileURI @ Sum.js:275 > instantiateArrayBuffer @ Sum.js:637 > await in instantiateArrayBuffer > instantiateAsync @ Sum.js:645 > createWasm @ Sum.js:713 > (anonymous) @ Sum.js:2761Understand this error > Sum.js:794 still waiting on run dependencies: > (anonymous) @ Sum.js:794 > setInterval > addRunDependency @ Sum.js:784 > createWasm @ Sum.js:674 > (anonymous) @ Sum.js:2761Understand this error > Sum.js:796 dependency: wasm-instantiate > (anonymous) @ Sum.js:796 > setInterval > addRunDependency @ Sum.js:784 > createWasm @ Sum.js:674 > (anonymous) @ Sum.js:2761Understand this error > Sum.js:799 (end of list) > (anonymous) @ Sum.js:799 > setInterval > addRunDependency @ Sum.js:784 > createWasm @ Sum.js:674 > (anonymous) @ Sum.js:2761Understand this error > > What am I doing wrong? > > Thanks for your help! > Thomas > > -- > You received this message because you are subscribed to the Google Groups > "emscripten-discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/emscripten-discuss/504419d6-cdcf-4eec-9a1e-e7f69f87a129n%40googlegroups.com > <https://groups.google.com/d/msgid/emscripten-discuss/504419d6-cdcf-4eec-9a1e-e7f69f87a129n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "emscripten-discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/emscripten-discuss/CAEX4NpTe_iw53aM%2BFCZ8YBz_Jo%2BMiGwJ6Gag24e-SAsBVOREYg%40mail.gmail.com.
