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Fixed in 2020.2.X

Fixed in 2018.4.X, 2019.4.X, 2020.1.X



Found in




Issue ID




Crash when declaring a replacement variable with "using" that encompasses any kind of Dictionary



Reproduction steps:
1. Open the attached project ("")
2. Open the "SampleScene"
3. Open the "test.cs" script in Visual Studio and set a breakpoint on line 11
4. Attach the VS debugger to Unity
5. Enter Play mode
6. When the breakpoint is hit, hover over "anyVariable" (if it doesn't crash, hover over "Start()" and hover over "anyVariable" again)

Reproducible with: 2018.4.19f1, 2019.3.4f1, 2020.1.0b1, 2020.2.0a2
Couldn't test with: 2017.4 since Visual Studio Unity debugging is not available in this stream

Last line in the Editor log before the crash (not always produced and the line might differ on different versions, this one is from 2020.2.0a2):
* Assertion: should not be reached at ..\mono\mini\debugger-agent.c:9672

Mac stacktrace:
#0 0x007fff647e92c2 in __pthread_kill
#1 0x007fff647536a6 in abort
#2 0x0000014caf5d42 in mono_log_write_logfile
#3 0x0000014cb09d4c in monoeg_g_logv
#4 0x0000014cb09ef1 in monoeg_assertion_message
#5 0x0000014c996889 in debugger_thread
#6 0x0000014cab1c0c in start_wrapper
#7 0x0000014cb25da2 in GC_inner_start_routine
#8 0x0000014cb25d37 in GC_start_routine
#9 0x007fff648a22eb in _pthread_body
#10 0x007fff648a5249 in _pthread_start
#11 0x007fff648a140d in thread_start

- Debugger sometimes displays a window showing "Getting DataTip..." right before the crash
- It doesn't seem to matter what kind of types the Dictionary is determined to store

  1. Resolution Note (fix version 2020.2):

    Fixed in 2020.2.0a7. Changed behavior on debugger-agent, if we can't parse new behavior we now return invalid_argument instead of asserting. Visual Studio 2019 will also address this issue in version: 16.6

  2. Resolution Note (fix version 2020.1):

    Fixed in 2020.1.0b9

  3. Resolution Note (fix version 2019.4):

    Fixed in 2019.4.1f1

  4. Resolution Note (fix version 2018.4):

    Fixed in 2018.4.24f1

Comments (2)

  1. PhaneV

    Oct 08, 2020 10:14

    PS: I removed the culprit "using SomeClass = System.Collection.Generic.Dictionary<..., ...>;" and it got fixed, so it's definitely the same issue.

  2. PhaneV

    Oct 08, 2020 10:09

    This happens to me 2019.3.7f1, and I see there's no resolution about the 2019.3.X track.
    Do you have any knowledge about it?

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