gulp sourcemaps doens't generate external map file

[lolaswift]

I love generator-m-ionic so much! Thank you guys for this amazing workflow tooling.
I have been trying to generate sourcemaps for Sentry like this:
if (options.minify) {
stream
.pipe(jsFilter)
.pipe($.ngAnnotate({
add: true,
sourcemap: true
}))
.pipe(stripDebug())
.pipe(sourcemaps.init())
.pipe($.uglify())
.pipe(sourcemaps.write('./map'))
.pipe(jsFilter.restore)
.pipe(cssFilter)
.pipe($.csso())
.pipe(cssFilter.restore);
}

However, I can't find anywhere the generated map file although the url gets appended to the app.js.
If I do it incline, then it works:
.pipe(sourcemaps.write())

Can you please give me some hint how can I achieve my goal? many thanks
-lola

@lolaswift having the same issue here. who did you manage to get it done? could you post your gulp task, please?

[lolaswift]

@ionut-tanasa I couldn't get it work. I am using incline map