Describe the bug
Lazygit panics on startup with index out of range [0] with length 0 in gocui/view.go writeCells. Transient retrying immediately succeeds.
Stack trace
panic: runtime error: index out of range [0] with length 0
goroutine 1 [running]:
github.com/jesseduffield/gocui.(*View).writeCells(0xc00011afc8?, 0x4b?, 0x0?, {0xc000988008?, 0xc0002a6a00?, 0x1906580?})
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/view.go:716 +0x2a8
github.com/jesseduffield/gocui.(*View).writeRunes(0xc00011afc8, {0xc0000c91a0, 0x3, 0x20})
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/view.go:803 +0x2b4
github.com/jesseduffield/gocui.(*View).writeString(...)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/view.go:829
github.com/jesseduffield/gocui.(*View).overwriteLines(0xc00011afc8, 0x1906580?, {0x0?, 0xc0000c9268?})
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/view.go:1716 +0x15b
github.com/jesseduffield/gocui.(*View).OverwriteLinesAndClearEverythingElse(0xc00011afc8, 0x0, {0x0?, 0x0?})
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/view.go:1732 +0xa5
github.com/jesseduffield/lazygit/pkg/gui/context.(*ViewTrait).SetViewPortContentAndClearEverythingElse(0xc0002c4a10?, {0x0?, 0x13?})
/home/runner/work/lazygit/lazygit/pkg/gui/context/view_trait.go:39 +0x2a
github.com/jesseduffield/lazygit/pkg/gui/context.(*ListContextTrait).HandleRender(0xc0002c4a00)
/home/runner/work/lazygit/lazygit/pkg/gui/context/list_context_trait.go:108 +0x102
github.com/jesseduffield/lazygit/pkg/gui.(*Gui).layout(0xc00027a308, 0xc0002f4000)
/home/runner/work/lazygit/lazygit/pkg/gui/layout.go:178 +0xc3f
github.com/jesseduffield/gocui.ManagerFunc.Layout(0x0?, 0xc00028fde0?)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:746 +0x19
github.com/jesseduffield/gocui.(*Gui).flush(0xc0002f4000)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:1203 +0xae
github.com/jesseduffield/gocui.(*Gui).processEvent(0xc0002f4000)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:831 +0x2cf
github.com/jesseduffield/gocui.(*Gui).MainLoop(0xc0002f4000)
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:796 +0xea
Analysis
writeCells attempts to index into a cells slice that was allocated with width=0, likely because the layout flush ran before gocui finished measuring terminal dimensions. The call path is:
layout → ListContextTrait.HandleRender → SetViewPortContentAndClearEverythingElse → OverwriteLinesAndClearEverythingElse → overwriteLines → writeRunes → writeCells → panic
Suspect: race between terminal dimension measurement and first render during startup.
Steps to reproduce
Open lazygit in a terminal. Occurs intermittently. Probably more reproducible immediately after terminal resize or rapid window focus change. Have seen same error four times now but cannot intentionally reproduce.
Expected behaviour
No panic. Either defer first render until dimensions are valid, or guard writeCells against zero-width view.
Version info
commit=80223c7fbbd0b86631a988834cbe88e267bb0bd9, build date=2025-11-01T09:43:19Z, build source=binaryRelease, version=0.56.0, os=linux, arch=amd64, git version=2.54.0
Related issues and PRs
Describe the bug
Lazygit panics on startup with
index out of range [0] with length 0ingocui/view.go writeCells. Transient retrying immediately succeeds.Stack trace
Analysis
writeCellsattempts to index into acellsslice that was allocated with width=0, likely because the layout flush ran before gocui finished measuring terminal dimensions. The call path is:layout→ListContextTrait.HandleRender→SetViewPortContentAndClearEverythingElse→OverwriteLinesAndClearEverythingElse→overwriteLines→writeRunes→writeCells→ panicSuspect: race between terminal dimension measurement and first render during startup.
Steps to reproduce
Open lazygit in a terminal. Occurs intermittently. Probably more reproducible immediately after terminal resize or rapid window focus change. Have seen same error four times now but cannot intentionally reproduce.
Expected behaviour
No panic. Either defer first render until dimensions are valid, or guard
writeCellsagainst zero-width view.Version info
commit=80223c7fbbd0b86631a988834cbe88e267bb0bd9, build date=2025-11-01T09:43:19Z, build source=binaryRelease, version=0.56.0, os=linux, arch=amd64, git version=2.54.0Related issues and PRs
index out of range [0] with length 0), different call site (findHyperlinkAtvia mouse move). Open.index out of range [0]panic, different root cause (git-todo-parser during rebase). Closed.writeCellspanic via TextArea refactor.