Where is the arm/armv6 source?

Trying to create a Poudriere jail for armv6
# poudriere jail -c -m http -v 11.0-RELEASE -a arm.armv6 -j 11_0armv6
[00:00:00] ====>> Cross-building ports for arm.armv6 on amd64 requires QEMU
[00:00:00] ====>> Creating 11_0armv6 fs... done
[00:00:00] ====>> Fetching MANIFEST for FreeBSD 11.0-RELEASE arm.armv6
fetch: http://ftp.freebsd.org/pub/FreeBSD/releases/arm/armv6/11.0-RELEASE/MANIFEST: Not Found
fetch: http://ftp.freebsd.org/pub/FreeBSD/releases/arm/armv6/11.0-RELEASE/MANIFEST: Not Found
[00:00:03] ====>> Error: Failed to fetch from http://ftp.freebsd.org/pub/FreeBSD/releases/arm/armv6/11.0-RELEASE/MANIFEST
[00:00:03] ====>> Error while creating jail, cleaning up.
[00:00:03] ====>> Removing 11_0armv6 jail...rm: /usr/local/poudriere/jails/11_0armv6: Device busy
AFAIK the source should be there:

But it is not. :(

Poudriere cannot find the source there.
There is no separate source for armv6
All FreeBSD source is the same for each revision.
svnlite co https://svn.freebsd.org/base/head
Pulls all source code for CURRENT. You can build i386, amd64, arm64 and armv6 from it.
svnlite co https://svn.freebsd.org/base/releng/11.0
This checks out FreeBSD-11.0

Checkout the /usr/src/sys/arm/conf/ folder in source it has all the directives for Arm architecture.
If you don't want to build the base system you can download it as an .img.xz. With mdconfig -f ...img can access its content and copy it to /usr/local/poudriere/jails/ directory. You an add it to poudriere with option -m null.
Ahh you added a Poudriere requirment to your post. I am not that knowledgeable about jails.
Can't you just copy the host OS /src over to your jails directory? Unless building for another FreeBSD version I think that would be just as easy.