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Azure app service seems to have been updated after 02utc.
There is now an error.
The following packages have unmet dependencies: libperl5.36 : Depends: perl-modules-5.36 (>= 5.36.0-7+deb12u2) but 5.36.0-7+deb12u1 is installed perl : Depends: libperl5.36 (= 5.36.0-7+deb12u1) but 5.36.0-7+deb12u2 is installed E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).
There is a version mismatch between libperl5.36, perl, and perl-modules-5.36
This does not fix it: apt --fix-broken install
I also tried
apt install perl=5.36.0-7+deb12u2 perl-modules-5.36=5.36.0-7+deb12u2 libperl5.36=5.36.0-7+deb12u2
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Hi Nick White,
After the Azure App Service update post-02 UTC, a version mismatch occurred between libperl5.36, perl, and perl-modules-5.36, causing unmet dependencies. Specifically, the system has conflicting versions of libperl5.36 and perl-modules-5.36. Running apt --fix-broken install doesn't resolve the issue.
To fix this, make sure all related packages (perl, perl-modules-5.36, and libperl5.36) have matching versions.
sudo apt update
sudo apt install perl=5.36.0-7+deb12u2 perl-modules-5.36=5.36.0-7+deb12u2 libperl5.36=5.36.0-7+deb12u2
sudo apt --fix-broken install
dpkg -l | grep perl
https://learn.microsoft.com/en-us/azure/app-service/overview-diagnostics
Thanks. I have tried that.
This is a Linux app service, so soesn't have sudo.
However,
apt install perl=5.36.0-7+deb12u2 perl-modules-5.36=5.36.0-7+deb12u2 libperl5.36=5.36.0-7+deb12u2
Gives:
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
perl-modules-5.36 is already the newest version (5.36.0-7+deb12u2).
perl-modules-5.36 set to manually installed.
libperl5.36 is already the newest version (5.36.0-7+deb12u2).
libperl5.36 set to manually installed.
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
perl : Depends: perl-base (= 5.36.0-7+deb12u2) but 5.36.0-7+deb12u1 is to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).
apt --fix-broken install
gives:
Get:1 http://deb.debian.org/debian-security bookworm-security/main amd64 perl-base amd64 5.36.0-7+deb12u2 [1609 kB]
Get:2 http://deb.debian.org/debian-security bookworm-security/main amd64 perl amd64 5.36.0-7+deb12u2 [239 kB]
Fetched 1847 kB in 0s (30.7 MB/s)
debconf: delaying package configuration, since apt-utils is not installed
(Reading database ... 27924 files and directories currently installed.)
Preparing to unpack .../perl-base_5.36.0-7+deb12u2_amd64.deb ...
Unpacking perl-base (5.36.0-7+deb12u2) over (5.36.0-7+deb12u1) ...
dpkg: error processing archive /var/cache/apt/archives/perl-base_5.36.0-7+deb12u2_amd64.deb (--unpack):
unable to make backup link of './usr/bin/perl' before installing new version: Operation not permitted
Errors were encountered while processing:
/var/cache/apt/archives/perl-base_5.36.0-7+deb12u2_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
Hi Nick White,
You're encountering a permission error when upgrading perl-base on your Linux Azure App Service. While other packages (perl, perl-modules-5.36, and libperl5.36) updated successfully to version 5.36.0-7+deb12u2, the perl-base upgrade fails due to this error:
dpkg: error ... unable to make backup link of './usr/bin/perl' before installing new version: Operation not permitted
Azure Linux App Services operate in a restricted environment that protects system files like /usr/bin/perl. While you can use apt to install packages, core system files can't be modified, and there is no sudo access for administrative tasks. This is why dpkg fails to update the system Perl binary, it doesn't have the necessary permissions to make the change.
Since upgrading system packages isn't supported in App Service, the best approach is to use a custom Docker container with the specific Perl versions you need. This allows you to control the OS and package versions, avoid issues from platform updates, and bypass permission restrictions in the Azure environment.
Create a Dockerfile with Debian 12 (Bookworm) as the base and install.
FROM debian:bookworm
RUN apt-get update && apt-get install -y \
perl=5.36.0-7+deb12u2 \
perl-modules-5.36=5.36.0-7+deb12u2 \
libperl5.36=5.36.0-7+deb12u2 \
perl-base=5.36.0-7+deb12u2
Deploy the image to Azure App Service using ACR or Docker Hub, then configure it under App Service → Deployment → Container Settings for full control over your runtime and packages.
Thanks. Yes, that is what I had decided too.
It would be a lot better if the App service was fixed though. This is something they changed when they updated it after 02z.
Hi Nick White,
Thank you for your feedback. I’m glad to hear that the Docker container solution aligns with your approach. Could you please let me know if the solution was helpful or if you need any further assistance.
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Hello Prabhavathi Manchala, We are facing the same issue and would be much better if its fixed in the App Service instead of changing to Docker which is do-able but will take time.
MS - I have submitted a service request.
It isn't sorry.
Docker may be the only solution, but will require significiant time and effort to investigate and implement, which we would prefer to avoid.
It would be better if Azure fixed the App Service conflicting versions of libperl5.36 and perl-modules-5.36.
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Hi Nick White,
Thanks a lot for sharing the detailed information, it really helps in narrowing down the issue.
Since Azure Linux App Service doesn’t allow system-level updates (like modifying /usr/bin/perl) and you prefer not to use Docker, you can avoid the libperl5.36 and perl-base version mismatch by installing Perl locally in the App Service’s writable home directory.
SSH into your App Service:
az webapp ssh --name <APP_NAME> --resource-group <RSGRP>
Download and compile Perl locally (in a writable path):
cd /home/site
wget https://www.cpan.org/src/5.0/perl-5.36.0.tar.gz
tar xzf perl-5.36.0.tar.gz
cd perl-5.36.0
./Configure -des -Dprefix=/home/site/perl
make -j$(nproc)
make install
Update App Settings > Configuration > Application settings:
PATH=/home/site/perl/bin:$PATH
PERL5LIB=/home/site/perl/lib/site_perl/5.36.0
This gives you a clean, isolated Perl 5.36 install in your app’s user space, no system conflicts, no version mismatches, no root access needed.
Hope this helps!
Let me know if anything doesn’t work as expected. Happy to help!
Thank you Gaurav Kumar.
That would be most helpful if it is a work-around until it gets fixed.
There is a problem with ./configure. Will investigate in the morning.
This is very close to being a work-around for the issue I think.
The first issue is that it can't be built on the Azure Web app, probably because of the bug. So a solution is to build it locally, tar it and upload to the App Service.
'which perl' now gives '/usr/bin/perl''.
However, the same issues remain.
Hi Nick White,
Thanks for the update, you’re absolutely right. Since Azure App Service doesn’t support full build environments (and likely blocks file operations like linking in /usr/bin), building Perl locally and uploading it is the cleanest workaround.
Build Perl locally (on your dev machine or a build agent):
wget https://www.cpan.org/src/5.0/perl-5.36.0.tar.gz
tar xzf perl-5.36.0.tar.gz
cd perl-5.36.0
./Configure -des -Dprefix=/home/site/perl
make -j$(nproc)
make install DESTDIR=$PWD/perl-out
cd perl-out/home/site
tar czf perl-custom.tar.gz perl
Extract it in /home/site/so your App Service uses the custom Perl:
cd /home/site
tar xzf perl-custom.tar.gz
Update App Settings in Azure portal under Configuration:
PATH=/home/site/perl/bin:$PATH
PERL5LIB=/home/site/perl/lib/site_perl/5.36.0
This way, app uses custom-built Perl without touching the system one (/usr/bin/perl). If needed, you can also symlink your local Perl to override the default at runtime though many scripts respect $PATH first.
Hope this helps!
Let me know if anything doesn’t work as expected. Happy to help!
Update - Microsoft has now fixed the issue.