Comment by eridius | Hacker News Reader

Comment by eridius | Hacker News Reader

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Every single macOS download I've tried of Eul has been completely broken. It simply won't launch. Doing so from the Terminal gives the following output:

  dyld: Library not loaded: libnanovg.a
    Referenced from: /Applications/eul.app/Contents/MacOS/./eul
    Reason: image not found

Weirdly, `otool -L eul` tells me that eul links against no dynamic libraries whatsoever (not even libSystem) and `otool -l eul` backs this up. I'm really curious how Eul managed to have zero dynamic library dependencies in the Mach-O headers and yet clearly still depends on them (especially because on macOS you must link against libSystem or you can't even make syscalls).

You need to unpack it via upx first. Then you'll be able to see the shared library dependencies with `otool`.

there is a libnanovg.a homebrew formula for now.

https://github.com/eul-im/eul/issues/83#issuecomment-3844554...

eul only supports twitter, slack and skype atm and the rest say they're coming later in march. The roadmap shows may-june.

You can make syscalls with inline assembly (SVC 0x80).

Not on macOS. macOS does not guarantee syscall compatibility between OS versions. The only supported mechanism for invoking syscalls is via libc.

You can do it, it’s how libsystem does it. A lot of AppStore apps use it for jailbreak testing too, e.g. testing sandbox integrity, or to call ptrace with PT_DENY_ATTACH. Apple lets these apps pass review and onto the AppStore.

Do you know how often, if ever, Apple ever changes the syscall table other than to add to it?

libSystem is provided by Apple. The fact that libSystem does it does not mean you can do it without libSystem, as libSystem is the one and only supported way to do this.

> Do you know how often, if ever, Apple ever changes the syscall table other than to add to it?

I don't know, but I'm pretty sure the answer is something other than "never".

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