How to fix "Error: the locale requested by the environment is invalid" during postgresql cluster upgrade (pg_upgradecluster) - postgresql

Question

After an upgrade from Ubuntu Server 14.04 to 16.04 I had to also upgrade my Postgres clusters from 9.3 to 9.5. The normal way to do that is to first drop the (empty) 9.5 cluster that the upgrade created:
# pg_dropcluster 9.5 main
and then to upgrade the old 9.3 cluster to 9.5:
# pg_upgradecluster 9.3 main
This however results in an error:
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = "en_US.UTF-8",
LC_ALL = (unset),
LC_PAPER = "nl_NL.UTF-8",
LC_ADDRESS = "nl_NL.UTF-8",
LC_MONETARY = "nl_NL.UTF-8",
LC_NUMERIC = "nl_NL.UTF-8",
LC_TELEPHONE = "nl_NL.UTF-8",
LC_IDENTIFICATION = "nl_NL.UTF-8",
LC_MEASUREMENT = "nl_NL.UTF-8",
LC_TIME = "nl_NL.UTF-8",
LC_NAME = "nl_NL.UTF-8",
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to a fallback locale ("en_US.UTF-8").
Error: The locale requested by the environment is invalid.
Error: Could not create target cluster
This means I could not upgrade to Postgres 9.5.
I checked all locale settings:
the en_US.UTF-8 locale exists and is properly generated as checked with locale -a (it shows en_US.utf8 in its list)
The file /etc/environment contains LC_ALL=en_US.UTF-8 and LANG=en_US.UTF-8
/etc/default/locale contains the same setting for LANG, LANGUAGE and LC_ALL
I can start Perl without any issue using "perl -e exit"
The error message is generated from the pg_createcluster script which is called from pg_updatecluster. But running pg_createcluster from the command line works just fine, without any issue.
Workaround for the issue:
I used the following workaround to at least get the conversion to work. I edited the /usr/bin/pg_upgradecluster script, as follows:
Find the code where it calls pg_createcluster by looking for the comment "create new cluster"
That code consists of a series of "push" statements, ending in the suspicious line:
delete $ENV{'LC_ALL'}
Notice that this LC_ALL is exactly the variable that is unset in the error message.
Comment out that delete comment by adding a '#' before it, then save.
This at least circumvents this problem and lets you run the upgrade.
My question: is this a bug in the pg_upgradecluster script, or is something else awry on my system?

Answer 1

had the same problem on an ubuntu 16.04 server. what helped in my case was to generate all the locales that appear in your listing of $ locale:
$ sudo locale-gen "en_US.UTF-8"
$ sudo locale-gen "nl_NL.UTF-8"
good luck!

Answer 2

In my case, it was complaining about
Error: The locale requested by the environment is invalid:
LANG: en_GB
LANGUAGE: en_GB:en
So I unset LANG and unset LANGUAGE and it worked.

Answer 3

For me, I have followed many suggestions and still didn't work.
The script mentioned
LC_TIME=en_UK but it's totally unrelated so I ignored it at first.
Turns out this was the problem and doing "unset LC_TIME" was all I needed.
Posting here in case it happened to someone else.

Answer 4

My quick way to disable that message: (macOS 12 Monterey M1)
Open Terminal -> Preferences -> Advanced tab -> uncheck to Set locale environment variables on startup

Answer 5

Just came across this in fresh Ubuntu + PostgresQL install, after all those years.. either way, the solution is:
apt-get install locales