Test behaves unexpected when using via-ir=true (the Yul pipeline)

[malteish]

Component

Forge

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.2.0 (e918c81 2023-06-27T00:04:31.801932823Z)

What command(s) is the bug in?

forge test

Operating System

Linux

Describe the bug

Problem

    /**
     * Demonstrate that tests don't work as expected with Yul
     * This test should fail, and does fail when run with via-ir=false.
     * But it succeeds when compiled with via-ir=true.
     */
    function testYul() public {
        uint256 time = block.timestamp;
        assertTrue(time == 1, "time is not 1 at the beginning");
        console.log("stored time before: ", time);
        // Problem 1: this warp changes the contents of the "time" variable, even though it shouldn't
        vm.warp(2 hours);
        console.log("stored time after: ", time);

        // Problem 2: none of these assertions fail, even though at least one should
        assertTrue(time == 1, "time is not 1 after warp");
        assertTrue(time == 2 hours, "time is not 1 after warp");

        console.log("This line is executed even though it shouldn't be reachable");
    }

1. time should always stay 1 in this test.
2. The test should fail because of the conflicting assertions.

Both expectations hold when compiling with via-ir=false, but neither of them holds when compiling with via-ir=true.

How to reproduce

Find the demo repository and follow the README.

Additional info

I found this problem when compiling my existing tests with via-ir=true for the first time. Now I am unsure how to proceed. In my opinion, this minimal example suggests some bug in foundry. Please advise on how to proceed.
I have not found any related issues.

Praise

Foundry rocks!

[mds1]

Closing as a duplicate, more info and workarounds are found in this linked issue and the other issues that comment links to: #4934 (comment)