Packages from p-u in "cannot be tested"

["Adam D. Barratt" <adam@adam-barratt.org.uk>]

Hi,

Recently I've noticed that a few packages from proposed-updates seem to 
be ending up in a state of "cannot be tested", with logs that suggest an 
issue locating the package.

For example, 
https://piuparts.debian.org/jessie-pu/untestable/libreoffice-dev-doc_1:4.3.3-2+deb8u7.log 
(and some others from the same source package) contains:

"
Start: 2017-05-02 09:23:27 UTC
Package libreoffice-dev-doc not found in jessie-proposed-updates

ret=-10001
End: 2017-05-02 09:23:27 UTC
"

and 
https://piuparts.debian.org/jessie-pu/untestable/firefox-esr_45.9.0esr-1~deb8u1.log 
similarly:

"
Start: 2017-05-02 09:23:27 UTC
Package firefox-esr not found in jessie-proposed-updates

ret=-10001
End: 2017-05-02 09:23:27 UTC
"

The previous packages that I saw in this state resolved themselves 
within a day or so, so I assume were rescheduled.

I don't remember seeing this behaviour before. Have I just been 
unobservant, or has something changed (or possible broken) with the 
testing?

Regards,

Adam