Writing to files, even in memory /tmp, is usually slower than writing directly to stdout. This is why upstream Thumbor, and our customizations, avoid it wherever possible.

In T335790#8821842, @AntiCompositeNumber wrote:

Writing to files, even in memory /tmp, is usually slower than writing directly to stdout. This is why upstream Thumbor, and our customizations, avoid it wherever possible.

I'd be interested to see how much slower it will make our operations in general though - relying on tool output seems brittle (as the issues linked have shown). We already make the tradeoff around storing files on disk vs in memory as one of our base differences from upstream Thumbor for scalability purposes. We already write to tempfiles for (at least) vips, svg, some exif operations, stl, thumbnail validity and a few other things.