QEMU_VER_SHORT not properly initialized in v4.9.7, causing startup crash

[Nininetto]

Description

In Quickemu v4.9.7, the internal variable QEMU_VER_SHORT is not properly initialized, which leads to a crash when the startup script attempts to use it.

This appears to happen because the QEMU_VER_LONG string sometimes contains extra characters (e.g., parentheses) that break the intended parsing.

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Steps to Reproduce

1. Install or run Quickemu v4.9.7
2. Run any virtual machine startup (e.g. quickemu --vm void-20250202-xfce-glibc.conf)
3. Observe the crash with an error referencing QEMU_VER_SHORT or malformed QEMU version output.

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Expected Behavior

The script should initialize QEMU_VER_SHORT correctly and continue launching the VM without crashing.

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Actual Behavior

The script fails to initialize properly and crashes early due to an invalid or empty QEMU_VER_SHORT value.

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Root Cause

The current line in the startup script:

QEMU_VER_SHORT=$(echo "${QEMU_VER_LONG%.*}" | sed 's/\.//g')

does not handle cases where QEMU_VER_LONG includes parentheses (e.g. 2.12.0(v2.12.0-19097-g85fa07f04ef)).

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Proposed Fix

I tested the following change, which resolves the issue:

QEMU_VER_SHORT=$(echo "${QEMU_VER_LONG%.*}" | sed 's/\.//g' | cut -d '(' -f 1)

This trims any parenthetical content from the version string before further processing.

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Environment

• Quickemu version: 4.9.7
• Host OS: Fedora 43
• QEMU version: qemu-10.1.2-1.fc43
• Shell: bash

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Additional Notes

After applying the fix, Quickemu runs as expected and VMs launch normally.
It might be worth sanitizing QEMU_VER_LONG more generally to handle future version formatting variations.

[zen2]

I got a similar problem: ERROR! QEMU 6.0.0 or newer is required, detected 10.1.2.
because QEMU_VER_SHORT get a value of 10 (instead of 100) that is compared to 60 (for 6.0).

I see that your QEMU_VER_SHORT origin affectation is coming from master branch and not 4.9.7 release one.
Master branch version fix actually my problem.

Your fix works but it is wrong:

$ QEMU_VER_LONG="2.12.0(v2.12.0-19097-g85fa07f04ef)"
$ echo "${QEMU_VER_LONG%.*}" | sed 's/\.//g' | cut -d '(' -f 1
2120

The result is 2120 instead of 212.

I propose the following fix:
QEMU_VER_SHORT=$(cut -d. -f1-2 <<< ${QEMU_VER_LONG/* }| tr -d .)

And it's possible to get rid of the awk fork too for QEMU_VER_LONG:
QEMU_VER_LONG=$(qemu-img --version | head -n 1 | cut -d' ' -f3-)

So to sum up:

QEMU_VER_LONG=$(qemu-img --version | head -n 1 | cut -d' ' -f3-)
QEMU_VER_SHORT=$(cut -d. -f1-2 <<< ${QEMU_VER_LONG/* }| tr -d .)

Note: all past, current and fixed code won't work if the second number in qemu version is greater or equal to 10. Major and minor version need to be handle separately to cover these cases.