Choosing Rights Host For Dependency Make I am working on on creating builds for windows, mac, and Unix. I am working on Ubuntu 18.04 but on a windows OS. I figured  out host-platform-triplets for windows and mac and generated prefixes for them but not sure how to determine the best Unix prefix. I was hoping to run this in a unix container out in gcp as a test harness. Any recommendations or guidance?
The following triplets are currently supported by Bitcoin Core's &quot;depends&quot; build system, assuming that's what you're talking about (and even if not, these are fairly standard). From https://github.com/bitcoin/bitcoin/blob/master/depends/README.md:

i686-pc-linux-gnu for Linux 32 bit
x86_64-pc-linux-gnu for x86 Linux
x86_64-w64-mingw32 for Win64
x86_64-apple-darwin18 for macOS
arm-linux-gnueabihf for Linux ARM 32 bit
aarch64-linux-gnu for Linux ARM 64 bit
powerpc64-linux-gnu for Linux POWER 64-bit (big endian)
powerpc64le-linux-gnu for Linux POWER 64-bit (little endian)
riscv32-linux-gnu for Linux RISC-V 32 bit
riscv64-linux-gnu for Linux RISC-V 64 bit
s390x-linux-gnu for Linux S390X

Added in master (which will become release version 22.0):

armv7a-linux-android for Android ARM 32 bit
aarch64-linux-android for Android ARM 64 bit
i686-linux-android for Android x86 32 bit
x86_64-linux-android for Android x86 64 bit

x86_64-pc-linux-gnu would be the most common one (targetting 64-bit x86 systems).