Common Open Source Problems (and how to fix them)

Things to always check first when troubleshooting

The first step in troubleshooting is to ensure that all of the following are true:

  • You are accessing the system with an SSH terminal

    • If you insist on using 5250, favor QP2TERM over QSH. If using QSH, ensure that the QIBM_MULTI_THREADED environment variable is set to Y before launching QSH

    • If you insist on using 5250, be aware that you are more likely to have problems, even if the above precautions are taken.

  • You have your PATH environment variable set properly. See Setting your PATH for guidance.

  • You are only editing files with only ASCII or UTF8-based editors, such as:

    • (Recommended) A cross-platform editor such as VSCode, Notepad++, jEdit, etc.

    • an SSH terminal UI-based editor, such as vim, nano, or jmacs.

  • You don’t have CRLF line terminators in your files. This can happen if you have edited your file from Windows and do not have your editor properly configured. If you are unsure, install the dos2unix package and run the resulting dos2unix utility on your file.

Shell cannot find yum command

When running the yum command from the command line, you encounter an error like:

  • -bash: yum: command not found

  • yum: not found

  • ksh: yum:  not found

  • qsh: 001-0019 Error found searching for command yum. No such path or directory.

Solution:

Add /QOpenSys/pkgs/bin to the beginning of your PATH environment variable. See Setting your PATH for details

Also, please don’t use QSH for open source tools. Use an SSH terminal instead.

yum can’t connect to the repository

When running yum from QSH, any commands that connect to the repository (install upgrade, etc) fail with a message like so:

yum install python3
https://public.dhe.ibm.com/software/ibmi/products/pase/rpms/repo/repodata/repomd.xml: [Errno 14] curl#6 - "getaddrinfo() thread failed to start"
Trying other mirror.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: ibm. Please verify its path and try again

Solution:

Run yum via SSH or the ACS Open Source Package Manager GUI. These are the ideal interfaces for working with yum and the rest of the open source ecosystem.

If you need to work from 5250, QP2TERM is preferred over QSH, but QSH will work as long as the QIBM_MULTI_THREADED environment variable is set to Y at the job level.

Up arrow doesn’t recall previous commands

Using arrow keys in the shell causes “garbage” to be displayed on the screen instead of cycling through command history (eg. ^[[A^[[D^[[C^[[C^[[D^[[A)

Solution:

The default shell used by SSH is bsh, which is very primitive. You will probably want to set bash as your default shell. See Setting bash as your shell for details.

User input is not working properly when running in 5250

Generally speaking, open source programs do not work well in 5250 interfaces such as QSH or Qp2Term. This may result in improper processing of control keys, phantom user input from previous commands, “garbage” characters printed to the screen, or a host of other issues.

Solution:

Please use an SSH terminal emulator and an SSH connection. Also, for usability, you probably want to set bash as your default shell. See Setting bash as your shell for details.

Python can’t find packages installed from ACS

After installing a Python package from ACS (eg. python3-Pillow), it can’t be found.

Solution:

  • Ensure you are running the correct version of Python for the package that was installed: python3 for packages with the python3 prefix and python2 for packages with the python2 prefix.

  • Also ensure that your PATH environment variable is set to find /QOpenSys/pkgs/bin before /QOpenSys/usr/bin and /usr/bin, especially if you potentially have other Pythons installed from 5733-OPS or Perzl rpms. See Setting your PATH for details.

NOTE: neither python rpm installed via yum creates a python symlink, so you cannot just run python.

Yum or RPM fails with “Error: Error: rpmdb open failed”

When Running a yum or rpm command you encounter

Error: Error: rpmdb open failed

Solution:

The rpm database has gotten corrupted. Please report this issue here.

The common solution is to rebuild the database with

/QOpenSys/pkgs/bin/rpm --rebuilddb

Yum or RPM fails with “db4 error(19) from dbenv->open: The specified device does not exist.”

Running yum you encounter an error like

error: db4 error(19) from dbenv->open: The specified device does not exist.
error: cannot open Packages index using db4 - The specified device does not exist. (19)
error: cannot open Packages database in /QOpenSys/var/lib/rpm
CRITICAL:yum.main:
Error: rpmdb open failed 

You probably have journalling on for an IFS directory that rpm is using. rpm uses mmap to open its database files, which is incompatible with journaling.

Note: When an ILE a application tries to mmap an IFS file which is being journaled it gets an error - ENOTSUP (operation not supported), however this gets mapped to PASE as ENODEV (no such device) which makes things confusing.

Solution:

Ensure that journaling is disabled/omitted for /QOpenSys/var/lib/rpm or any subdirectory. You can use option 8 from WRKLNK to view the journaling attributes of a given file or directory.

Commands are failing in QSH

Many commands will fail in QSH for many reasons! However, a common reason is related to the QSH behavior that disallows multithreaded applications by default. The resulting error message may or may not be descriptive, but here are some examples.

git:

error: cannot create async thread: Resource temporarily unavailable
fatal: fetch-pack: unable to fork off sideband demultiplexer 

node/npm:

[335708]: ../src/node_platform.cc:61:std::unique_ptr<unsigned int> node::Work   erThreadsTaskRunner::DelayedTaskScheduler::Start(): Assertion `(0) == (uv_thr   ead_create(t.get(), start_thread, this))' failed.
qsh: 001-0078 Process ended by signal 5.                                     

curl:

curl: (6) getaddrinfo() thread failed to start 

java (openjdk):

Error: Port Library failed to initialize: -1             
Error: Could not create the Java Virtual Machine.        
Error: A fatal exception has occurred. Program will exit.

Solution:

As mentioned earlier, the optimal solution is to connect with an SSH client. If you insist on using 5250, favor QP2TERM over QSH. If using QSH,you must ensure that the QIBM_MULTI_THREADED environment variable is set to Y before launching QSH.

Ansible fails with “No python interpreters found”

If running Ansible against an IBM i endpoint, it can sometimes fail with the following warning issued:

[WARNING]: No python interpreters found for host __________ (tried ['/usr/bin/python', 'python3.7', 'python3.6', 'python3.5', 'python2.7', 'python2.6', '/usr/libexec/platform-python', '/usr/bin/python3', 'python'])

This is because Ansible does not currently know how to find the RPM-installed Python interpreters on IBM i (GitHub issue pending).

Solution:

This can often be corrected by fixing the PATH of the user that you are using to connect with Ansible.

It’s likely best, however, to be more explicit, so you’re not as susceptible to variations in server environments. To do so, you can set Ansible’s ansible_python_interpreter inventory variable to a fully-qualified path, namely /QOpenSys/pkgs/bin/python3.9 (use version 3.6 if absolutely needed). This can be done in the various ways. See this doc.

Ansible (or another SSH-based tool) asks for a password

If you’d like to run Ansible (or similar SSH-based tools) non-interactively and without a password, it can sometimes still ask for a user password (and therefore fail in non-interactive environments).

Solution:

You need to configure password-less authentication per this doc, just use the same Linux and IBM i system and user. Alternatively, once you install your public key on the IBM i server, provide your private key to ansible by way of the ansible_ssh_private_key_file inventory variable. More info here. Always make sure that your private key is kept secure!

“intended for a different operating system” when running IBM i 7.4

If you installed the open source “bootstrap” from a very early version, and have since upgraded to IBM i 7.4, you may see errors like the following when trying to install a package:

Transaction Check Error:
  package make-gnu-4.2-2.ppc64 is intended for a different operating system

Solution:

The very early versions of the bootstrap did not know IBM i 7.4 existed. You can work around this issue by adding an OS compatibility setting to the RPM configuration, as shown in the following command:

echo 'os_compat: ibmi7.4: ibmi ibmi7.1 ibmi7.2 ibmi7.3' >> /QOpenSys/pkgs/lib/rpm/rpmrc

It is then recommended to get the latest versions of rpm, yum, and ibmi-repos packages:

/QOpenSys/pkgs/bin/yum install -y rpm yum ibmi-repos

I’m still having issues

If you are having an issue that’s not listed above or the solution provided did not help, please open a ticket here.