apt-get failing to show progress with yes command

BTW, forgot to mention if the command is run as:
yes "" | apt-get -y install tftpd-hpa >/dev/null
It finishes successfully.

Thanks Steven! This is fixed in the current debian/sid branch in commit a11f6c973bc0dc226d8953e3edb6333d526c3143. But I'm not overly happy with that fix as its a relatively big hammer so I will see if I can come up with something better.

I reworked the pty handling in https://github.com/mvo5/apt/commits/bugfix/lp1324399-pty-stdin and it should work now with the commands that you outlined. Probably too big for a SRU, so we can go with a11f6c973bc0dc226d8953e3edb6333d526c3143.

Hello Steven, or anyone else affected,

Accepted apt into trusty-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/apt/1.0.1ubuntu2.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

With http://launchpad.net/ubuntu/+source/apt/1.0.1ubuntu2.2 , the command finishes with this output.

$ yes "" | sudo apt-get -y install tftpd-hpa
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  tftpd-hpa
0 upgraded, 1 newly installed, 0 to remove and 47 not upgraded.
Need to get 0 B/38.2 kB of archives.
After this operation, 151 kB of additional disk space will be used.
Preconfiguring packages ...
E: Can not write log (Is stdout a terminal?) - tcgetattr (25: Inappropriate ioctl for device)
Selecting previously unselected package tftpd-hpa.
(Reading database ... 238423 files and directories currently installed.)
Preparing to unpack .../tftpd-hpa_5.2-7ubuntu3_amd64.deb ...
Unpacking tftpd-hpa (5.2-7ubuntu3) ...
Processing triggers for ureadahead (0.100.0-16) ...
Processing triggers for man-db (2.6.7.1-1) ...
Setting up tftpd-hpa (5.2-7ubuntu3) ...
tftpd-hpa start/running, process 28508
Processing triggers for ureadahead (0.100.0-16) ...

This SRU has been shadowed by a security update and need to be re-merged.

I could reupload the fix that was previously uploaded, but I wonder if it is worth it since it remained unverified last time for two months.

I am not sure what you mean by two months. apt was accepted into trusty-proposed on 2014-07-15, and I verified the fix four days later on 2014-07-19.

I believe I was referring to the fact that the SRU as whole (which includes multiple bug reports) was not verified in a timely fashion, not that this bug was unverified.