Developer SpecterDev has published an update to the PS4 Homebrew development toolchain OpenOrbis.
Although this is a less “meaty” update than release 0.5 in August, version 0.5.1 still brings some significant improvements and bug fixes, from multiple devs in the scene (see changelog below for details).
What is the OpenOrbis PS4 Toolchain

The OpenOrbis toolchain is basically everything you need to develop Homebrew for the PS4, without having to rely on “leaked” official tools from Sony. you can find more details on the toolchain’s official github.
You’ll need a hacked PS4 to run any homebrew created with this set of tools.
SpecterDev warns that you’ll want to use LLVM 10 or below for the time being, as LLVM 11 breaks some compatibility with the toolchain. (source)
OpenOrbis Toolchain 0.5.1 Changelog

  • Fixed various discrepancies between BSD and MUSL including function prototypes, structure definitions, and macros!
  • Added Docker container support (thanks alazif)!
  • Added proper TLS support (thanks sleirsgoevy)!

  • Added a battery of unit tests for issues addressed in v0.5.1. These tests will be kept up to date with future additions to attempt to improve release qualities.
  • Fixed an issue where MUSL was not thread-safe due to custom CRT.
  • Added support ‘+’ and ‘-‘ escaping in NIDs (thanks sleirsgoevy).
  • Fixed an issue where relocations could refer to incorrect symbols due to not accounting for an additional SECTION entry (thanks sleirsgoevy).
  • Fixed copy/paste induced bugs in the script (thanks alazif).
  • Fixed a minor issue where the __bswap32 macro in the endian include header produced compiler warnings (thanks astrelsky).

(source: OpenOrbis 0.5.1 changelog)

PS4: OpenOrbis Toolchain updated to 0.5.1 -