"Duplicate symbol definition" error when using incremental compilation with zig sqlite library

glitchcake · October 28, 2025, 5:21am

I am running zig build test -fincremental --watch in a minimal repo having had been created with zig init and having had this zig-sqlite package added.

When I make changes to a file, I get compile errors like this until I kill and restart the zig build test process:

Build Summary: 2/5 steps succeeded; 1 failed; 1/1 tests passed
test transitive failure
└─ run test transitive failure
   └─ compile test Debug native 273 errors

test
└─ run test
   └─ compile test Debug native 273 errors
error: duplicate symbol definition: sqlite3_status64
    note: defined by .zig-cache/o/0d9f330882b0082415928ee467f2861d/sqlite3.o
    note: defined by .zig-cache/o/0d9f330882b0082415928ee467f2861d/sqlite3.o
error: duplicate symbol definition: sqlite3_mutex_enter
    note: defined by .zig-cache/o/0d9f330882b0082415928ee467f2861d/sqlite3.o
    note: defined by .zig-cache/o/0d9f330882b0082415928ee467f2861d/sqlite3.o
[it goes on like this for a bit, and then ends with]
error: 273 compilation errors

Build Summary: 2/5 steps succeeded; 1 failed; 1/1 tests passed
test transitive failure
└─ run test transitive failure
   └─ compile test Debug native 273 errors

That is, it works the first time I start the process, but once I make any change and save to trigger the watcher to run again, these duplicate symbol errors show up. Does anyone know why this would be happening, or how to fix it if possible?

Same behavior observed with zig 0.15.1 and 0.15.2

Cheers and thank you!

ScottRedig · October 28, 2025, 7:39am

Incremental should not have any different behavior, so assuming your code works when not using incremental, that’s a bug.

Searching on github, look to see if any of these issues are relevant: GitHub · Where software is built

If they aren’t, then file a new issue on github.

glitchcake · October 28, 2025, 12:48pm

I don’t use Github, but thanks anyways

glitchcake · October 28, 2025, 1:15pm

I spaced over the first part; doing a search is a great call, thanks. I did find this:

github.com/ziglang/zig

"duplicate definition" error on incremental rebuild with C source

opened 03:03PM - 04 Sep 25 UTC

djpohly

bug linking incremental compilation

### Zig Version 0.16.0-dev.168+d51d18c98 ### Steps to Reproduce and Observed B…ehavior 1. Create a project which combines C and Zig sources using `addCSourceFile`. For example ([download full MRE](https://github.com/user-attachments/files/22141522/repro.tar.gz)): #### **answer.c** ```c unsigned char answer(void) { return 42; } ``` #### **main.zig** ```zig extern fn answer() u8; pub fn main() u8 { return answer(); } ``` 1. In one terminal: `zig build --watch -fincremental`. Build succeeds; leave this running. ``` Build Summary: 3/3 steps succeeded install success └─ install zig_bugtest success └─ compile exe zig_bugtest Debug native success 433ms ``` 1. In another terminal, `touch main.zig`. Incremental rebuild fails: ``` install └─ install zig_bugtest └─ compile exe zig_bugtest Debug native 1 errors error: duplicate symbol definition: answer note: defined by main.o note: defined by .zig-cache/o/947b2dda26b0849e5693c298de54308f/answer.o error: 1 compilation errors Build Summary: 0/3 steps succeeded; 1 failed install transitive failure └─ install zig_bugtest transitive failure └─ compile exe zig_bugtest Debug native 1 errors ``` The same thing happens if you `touch answer.c`. ### Expected Behavior Successful rebuild (or better, no rebuild, since the file contents did not change).