pmb.build: use pigz instead of gzip (MR 2252)

This is multithreaded, and by consequence much much faster than default
gzip. Since we switched to running gzip from the native chroot we also
changed from running it in the fastest mode, now we're running it with
-9 it can be pretty slow on any kind of mobile hardware.

Signed-off-by: Caleb Connolly <caleb@postmarketos.org>

pmb/build/init.py

@@ -20,6 +20,9 @@ def init_abuild_minimal(args: PmbArgs, chroot: Chroot=Chroot.native()):
     if os.path.exists(marker):
         return
 
+    # pigz is multithreaded and makes compression must faster, we install it in the native
+    # chroot and then symlink it into the buildroot so we aren't running it through QEMU.
+    pmb.chroot.apk.install(args, ["pigz"], Chroot.native(), build=False)
     pmb.chroot.apk.install(args, ["abuild"], chroot, build=False)
 
     # Fix permissions

pmb/chroot/mount.py

@@ -107,7 +107,7 @@ def mount_native_into_foreign(args: PmbArgs, chroot: Chroot):
     if not musl_link.is_symlink():
         pmb.helpers.run.root(args, ["ln", "-s", "/native/lib/" + musl,
                                     musl_link])
-        pmb.helpers.run.root(args, ["ln", "-sf", "/native/bin/busybox", "/usr/local/bin/gzip"])
+        pmb.helpers.run.root(args, ["ln", "-sf", "/native/usr/bin/pigz", "/usr/local/bin/pigz"])
 
 def remove_mnt_pmbootstrap(args: PmbArgs, chroot: Chroot):
     """ Safely remove /mnt/pmbootstrap directories from the chroot, without