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.

In our Eclipse-based application we see a ton of prints on standard error: gtk_box_gadget_distribute: assertion 'size >= 0' failed in GtkScrollbar

See Eclipse bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=538000

We've opened an issue in the GTK+ issue tracker with a GTK3-only reproducer: https://gitlab.gnome.org/GNOME/gtk/-/issues/210

The GTK+ issue has been open for 2 years without a fix, a patch suggestion was made 3 months ago.

The standard error is flooded and made useless by this error. Debugging Eclipse is also impeded, since the standard error is mixed with the error log output, making it hard to find actually useful output. In our product we had to redirect the error stream to prevent the user from seeing the unexpected GTK+ errors.

Where are you experiencing the behavior? What environment?
RHEL 7.4 with GTK3 version:

gtk3-3.22.30-3.el7.x86_64

We would like a fix in GTK3.

Red Hat Enterprise Linux 7 shipped it's final minor release on September 29th, 2020. 7.9 was the last minor releases scheduled for RHEL 7.
From intial triage it does not appear the remaining Bugzillas meet the inclusion criteria for Maintenance Phase 2 and will now be closed. 

From the RHEL life cycle page:
https://access.redhat.com/support/policy/updates/errata#Maintenance_Support_2_Phase
"During Maintenance Support 2 Phase for Red Hat Enterprise Linux version 7,Red Hat defined Critical and Important impact Security Advisories (RHSAs) and selected (at Red Hat discretion) Urgent Priority Bug Fix Advisories (RHBAs) may be released as they become available."

If this BZ was closed in error and meets the above criteria please re-open it flag for 7.9.z, provide suitable business and technical justifications, and follow the process for Accelerated Fixes:
https://source.redhat.com/groups/public/pnt-cxno/pnt_customer_experience_and_operations_wiki/support_delivery_accelerated_fix_release_handbook  

Feature Requests can re-opened and moved to RHEL 8 if the desired functionality is not already present in the product. 

Please reach out to the applicable Product Experience Engineer[0] if you have any questions or concerns.  

[0] https://bugzilla.redhat.com/page.cgi?id=agile_component_mapping.html&product=Red+Hat+Enterprise+Linux+7