Running symlinked binary results in error: Cannot find the assets

[andornaut]

Steps to reproduce

1. Download and unzip PS1_2011_ROM_US.zip into /opt/ibmps1/roms/2011
2. Install ibmulator v0.12 release to /opt/ibmps1/ibmulator
3. Symlink binary: sudo ln -s /opt/ibmps1/ibmulator/bin/ibmulator /usr/local/bin/
4. Run ibmulator, exit
5. Edit ~/.config/ibmulator/ibmulator.ini, set: romset=/opt/ibmps1/roms/2011/FC0000.BIN
6. Run ibmulator

Expected results

IBMulator starts successfully

Actual results

$ ibmulator 
[INF0] prg | IBMulator 0.12 started
[ERR0] prg | Cannot find the assets!
[INF0] prg | Program stop

or

$ /usr/local/bin/ibmulator 
[INF0] prg | IBMulator 0.12 started
[ERR0] prg | Cannot find the assets!
[INF0] prg | Program stop

Observations

Running the binary directly (not via a symlink) works as expected:

$ /opt/ibmps1/ibmulator/bin/ibmulator 
[INF0] prg | IBMulator 0.12 started
[INF0] prg | Calibrating...
[INF0] prg | This system has high precision timing. Impressive, very nice.
[INF0] mch | Loading ROM file '/opt/ibmps1/roms/2011/FC0000.BIN'
[...]

Environment

IBMulator version: 0.12 OS: Linux Distribution: Ubuntu 20.10 Kernel: 5.8.0-53-generic

[barotto]

Hi, first of all thank you for testing IBMulator on Linux.

The "Cannot find the assets!" error is about the missing ibmulator directory in share (I guess it should be a bit more descriptive). IBMulator's file structure follows the common unix convention of bin and share dirs so the executable looks into ../share/ibmulator/ for its assets at launch.

I think the solution for you would be to create a symlink in /usr/local/share/ to /opt/ibmps1/ibmulator/share/ibmulator.

About the first step in "Steps to reproduce", there's no need to unzip the romset. And actually for international romsets splitted in 2 bin files it would not even work, they must be kept zipped.

[andornaut]

I think the solution for you would be to create a symlink in /usr/local/share/ to /opt/ibmps1/ibmulator/share/ibmulator.

That may work.

Do note that it does work without that workaround if I execute ibmulator from /opt/ibmps1/ibmulator/bin/ibmulator. This suggests to me that one of the searched paths (for share) is a relative path from the location of the binary, which is why it finds /opt/ibmps1/ibmulator/share if executed as /opt/ibmps1/ibmulator/bin/ibmulator. I believe that this could be fixed by resolving/following the symlink prior to deriving the relative paths. "realpath /usr/local/bin/ibmulator".

I worked around this issue by creating a bash script in /usr/local/bin/ibmulator instead of a symlink:

#!/bin/bash
cd /opt/ibmps1/ibmulator
./bin/ibmulator

About the first step in "Steps to reproduce", there's no need to unzip the romset.

Thanks for letting me know! :smile:

[barotto]

one of the searched paths (for share) is a relative path from the location of the binary

Yes, that's exactly what it does. Another (undocumented) way to specify the assets dir is by using an environment variable called DATA_HOME. A third one is by placing the assets in $XDG_DATA_HOME/ibmulator, when the XDG base dir spec is followed by the OS. (now thinking of it I should also add $HOME/.local/share/ibmulator to the mix...)

I believe that this could be fixed by resolving/following the symlink prior to deriving the relative paths.

This is a good suggestion. I actually call realpath() at a later stage but the path needs to be resolved for the binary first. I'll fix this on the next version. Thanks!

[andornaut]

A third one is by placing the assets in $XDG_DATA_HOME/ibmulator, when the XDG base dir spec is followed by the OS. (now thinking of it I should also add $HOME/.local/share/ibmulator to the mix...)

$XDG_DATA_HOME defaults to (and is usually) set to $HOME/.local/share.

Just a minor note: I think you'd want to include $HOME/.local/share only if $XDG_DATA_HOME is undefined or empty, and otherwise use the path denoted by $XDG_DATA_HOME without also adding $HOME/.local/share.

No biggie either way, though.

[barotto]

I think you'd want to include $HOME/.local/share only if $XDG_DATA_HOME is undefined or empty

Yep, I agree. Fixed on unstable. Thanks again.