poudriere use for head or stable/11 variant: patch internal-paths to use?

[Mark Millard]

[This question is biased to my powerpc family experiments, doing
things directly on the powerpc family.]

Unlike for "ports" in poudriere and -m none -f none -M <path>
use (ufs file system) the jail alternative seems to just be
patches:

   jail
. . .
     Here are the options associated with the jail
 command.
. . .
     -P patch     Apply the specified patch
                  to the source tree before building
                  the jail.

but nothing seems to specify the form of the patch
for paths:
(I use svn for /usr/src historically: these are from
svnlite diff outputs.)

Index: contrib/llvm/lib/Target/PowerPC/PPCInstrInfo.td
===================================================================
--- contrib/llvm/lib/Target/PowerPC/PPCInstrInfo.td     (revision 310236)
+++ contrib/llvm/lib/Target/PowerPC/PPCInstrInfo.td     (working copy)
. . .

vs.

Index: /usr/src/contrib/llvm/lib/Target/PowerPC/PPCInstrInfo.td
===================================================================
--- /usr/src/contrib/llvm/lib/Target/PowerPC/PPCInstrInfo.td    (revision 310236)
+++ /usr/src/contrib/llvm/lib/Target/PowerPC/PPCInstrInfo.td    (working copy)

vs.

whatever.

What is expected for paths? (And I suggest the command
documentation give an explicit hint or pointer to something
that has a hint.)

If I interpret the documents correctly poudriere will not
use my /usr/src/ : -P patch-file is the technique and I
need something like "-m svn+https".

Why I care:

I normally have patches for powerpc land as I experiment with
libc++ and clang or devel/powerpc64-xtoolchain-gcc for
targeting powerpc64 and powerpc buildworld and buildkernel
(simplified statement). I also have my own KERNCONF's (that
include the standard ones).

Be it head or stable/11 for now I need a variation of them
for my context, including building ports (at least for
system-clang based experiments).

Note: It may be some time before I do anything that adds
kernel modules so kernel-building does not have to be
involved at this time for powerpc64 or powerpc. But this
might not last.

===
Mark Millard
markmi at dsl-only.net