QEMU only supports the two most recent versions of macOS (see https://www.qemu.org/docs/master/system/build-platforms.html). Support for older versions has been removed (see https://git.qemu.org/?p=qemu.git;a=commitdiff;h=483644c25b93236001), so if you still want to use QEMU on such an old system, you better use an older version of QEMU instead.
** Changed in: qemu Status: New => Won't Fix -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1887318 Title: impossible to install in OSX Yosemite 10.10.5 Status in QEMU: Won't Fix Bug description: the Brew method has glib problems, glib is impossible to install. the MacPorts method has a very long .log file. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1887318/+subscriptions