Cannot enable the module on Drupal 8

Following!

I am on Drupal 8.9.1 installed upgrade_status through composer, but when I try to enable I get this error

"Error message Upgrade Status should be used on a Drupal 8 site to detect deprecated APIs present. It does not in itself know about deprecated APIs and Drupal 9 does not have Drupal 8's deprecated APIs anymore."

https://www.drupal.org/files/issues/2020-06-18/3152276.patch

That patch only duplicates the problem code...I think...

I ran into the same problem. After installing Status Upgrade module 2.8 via composer, i am not able to enable this module. Tried the patch #3 but doesn't fix it. I'm also running Drupal 8.9.1

Hello, I have the same problem with version 2.8 installed by composer, Drupal is on version 8.8.8.

The patch from message #3 did not work, any other ideas?

if (version_compare('9.0.0', \Drupal::VERSION) >= 0) {
should read
if (version_compare('9.0.0', \Drupal::VERSION) < 0) {
or
if (version_compare(\Drupal::VERSION, '9.0.0' ) >= 0) {

EDIT
My mistake, error should be provided in case of 9.0.0 or higher
if (version_compare('9.0.0', \Drupal::VERSION) < 1) {
or
if (version_compare('9.0.0', \Drupal::VERSION) <= 0) {
as written in the patch

Considering you can't use the module on the intended version of Drupal, set to major.

Oops. I wonder how can our automated testing install it on 8.9?

So as per https://www.php.net/manual/en/function.version-compare.php

By default, version_compare() returns -1 if the first version is lower than the second, 0 if they are equal, and 1 if the second is lower.

So

if (version_compare('9.0.0', \Drupal::VERSION) >= 0) {

Is indeed entirely wrong as an error condition. It would fire if the version would be supported but also for 9.0.0. It should be <=.

Released https://www.drupal.org/project/upgrade_status/releases/8.x-2.9. So sorry for this mistake. Hope it all works now.

Backstory at https://twitter.com/gaborhojtsy/status/1274414707617783808?s=19 :)

Still wrong in my opinion. Would allow install on 9.0.0 !

Hm why? Returns 0 if they are equal no?

Indeed, equal returns 0. My understanding is you don't want it on 9.0.0. Which means < 0, not <= 0.

No. Using the project on any version of Drupal 9 would return a very misleading and limited result set. People should use this project on Drupal 8. Yes I could also make it incompatible with Drupal 9 with composer but that does not make it impossible for people to get it from the tarball and/or complain that they wanted to install but got a generic Drupal / composer message. This is the only way to give specific actionable guidance to people who try to use it on the wrong Drupal major version.

My bad. Was convinced it was wrong, but I stand corrected. Thanks and sorry for the inconvenience.

It's fine, thanks for reporting the original problem :)

I had the same problem, but now installing it without problem! thanks for fixing it! :)