When I had a need for a Dockered cross-compiler, I found that Gentoo and crossdev [0] were amazing. Because of Gentoo's philosophy of distributing source only,

When I had a need for a Dockered cross-compiler, I found that Gentoo and crossdev [0] were amazing. Because of Gentoo's philosophy of distributing source only, the toolchain was built inside the container, and using fresh versions of each tool. A few additional steps were involved with setting up an overlay, but it was smooth sailing from there, and people on #gentoo-mips were eager to help. [0] https://wiki.gentoo.org/wiki/Cross_build_environment https://wiki.gentoo.org/wiki/Cross_build_environment