RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Description of problem:
When using ssh -tt as the remote shell for rsync, the transfer fails with error:
rsync error: error in rsync protocol data stream (code 12) at io.c(1134) [sender=3.0.6]

Version-Release number of selected component (if applicable):
rsync 

How reproducible:
Easily reproducible.

Steps to Reproduce:
1. echo test >> test
2. rsync --rsh="ssh -tt" test root@rhel:/root/test

Actual results:
    tcgetattr: Invalid argument
    unexpected tag 87 [sender]
    rsync error: error in rsync protocol data stream (code 12) at io.c(1134) [sender=3.0.6]

Also, the file does not transfer.

Expected results:
No error, and the file should transfer.

Additional info:
Same error message as BZ# 959824. Different reproduction steps though.

I don't think tools like rsync are generally ready to transfer data over a pseudo terminal and I wouldn't expect it to work. The transfers rsync is doing are of binary nature and any layer that works with special characters naturally breaks that.

I am curious about the reason for using double '-t' as the meaning of that is to force TTY allocation even when it clearly doesn't make sense (e.g. the local side is a daemon that wants to transfer data, and not a terminal session).

Is there any reason to use '-tt' except to deliberately break any binary protocol over the SSH transport (e.g. for testing purposes)?