BTW, if you want to get things working quickly you should be able use `-sSINGLE_FILE_BINARY_ENCODE=0`. This setting was added specifically in case a bug this showed up/
cheers, sam On Fri, Oct 31, 2025 at 8:54 AM Thomas Grund <[email protected]> wrote: > Thanks for analyzing! > > Thomas > > [email protected] schrieb am Donnerstag, 30. Oktober 2025 um 18:32:45 > UTC+1: > >> 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/5b591cef-ad8e-467f-95dc-b43719e21086n%40googlegroups.com > <https://groups.google.com/d/msgid/emscripten-discuss/5b591cef-ad8e-467f-95dc-b43719e21086n%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/CAL_va28rOKEOnYUfSs%2BJL4Do4RZ9PWQnJ7c17Yd0DSOZeBQK6Q%40mail.gmail.com.
