From 4495c197c44bb6c4d236085fdf14ee973f18e103 Mon Sep 17 00:00:00 2001
From: Oscar Smith <oscardssmith@gmail.com>
Date: Fri, 24 Jul 2026 11:00:29 -0400
Subject: [PATCH 1/4] Fix highlighting regression from using Highlights.jl
 incorrectly

---
 Project.toml      |  2 +-
 src/precompile.jl |  5 +----
 src/printing.jl   | 43 ++++++++-----------------------------------
 test/misc.jl      | 23 +++++++++++++++++++++++
 4 files changed, 33 insertions(+), 40 deletions(-)

diff --git a/Project.toml b/Project.toml
index 1875225..19e08f8 100644
--- a/Project.toml
+++ b/Project.toml
@@ -13,7 +13,7 @@ REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
 tree_sitter_julia_jll = "52be201e-a5e9-5cfe-8bf2-2dc4b062171c"
 
 [sources]
-TerminalRegressionTests = {url = "https://github.com/JuliaDebug/TerminalRegressionTests.jl", rev = "kc/terminal-1.12-support"}
+TerminalRegressionTests = {url = "https://github.com/JuliaDebug/TerminalRegressionTests.jl", rev = "675923307baa801cd32f5774b4b375723c650b54"}
 
 [compat]
 CodeTracking = "2, 3"
diff --git a/src/precompile.jl b/src/precompile.jl
index 08c62ce..2da95a6 100644
--- a/src/precompile.jl
+++ b/src/precompile.jl
@@ -42,10 +42,7 @@ end
     # active REPL), which the scripted session above does not exercise
     precompile(RunDebugger, (Frame,))
 
-    # Clean up global state the workload mutated. The highlight cache in
-    # particular holds tree-sitter pointers that must not be serialized into
-    # the package image.
-    _highlight_cache[] = nothing
+    # Clean up global state the workload mutated.
     empty!(WATCH_LIST)
     JuliaInterpreter.remove()
     _ALT_SCREEN[] = false
diff --git a/src/printing.jl b/src/printing.jl
index c22abcf..aa75560 100644
--- a/src/printing.jl
+++ b/src/printing.jl
@@ -402,29 +402,10 @@ function compute_source_offsets(code::AbstractString, current_offsetline::Intege
     startoffset, stopoffset
 end
 
-# `Highlights.highlight` creates a tree-sitter parser and compiles the
-# highlight query on every call (~30 ms) — far too slow for a status print
-# that highlights every variable line. Cache them for the session.
-mutable struct HighlightCache
-    parser::Any
-    query::Any
-    theme::Any
-    theme_name::String
-end
-const _highlight_cache = Ref{Union{HighlightCache, Nothing}}(nothing)
-
-function highlight_cache()
-    cache = _highlight_cache[]
-    if cache === nothing || cache.theme_name != _current_theme[]
-        lang = Highlights.resolve_language(:julia)
-        parser = Highlights.TreeSitter.Parser(lang)
-        query = Highlights.TreeSitter.Query(lang, ["highlights"])
-        theme = Highlights.load_theme(_current_theme[])
-        cache = HighlightCache(parser, query, theme, _current_theme[])
-        _highlight_cache[] = cache
-    end
-    return cache
-end
+# Pass the grammar module rather than the `:julia` symbol: symbol lookup goes
+# through `Base.identify_package`, which only sees the active project's direct
+# deps and so fails when Debugger is an indirect dependency.
+import tree_sitter_julia_jll
 
 function highlight_code(code; context=nothing)
     if context !== nothing && !get(context, :color, false)
@@ -432,20 +413,12 @@ function highlight_code(code; context=nothing)
     end
     _syntax_highlighting[] || return code
     try
-        cache = highlight_cache()
-        tokens = Highlights.highlight_tokens(cache.parser, cache.query, code)
         return sprint(context=context) do io
-            Highlights.format(io, MIME("text/ansi"), tokens, code, cache.theme, :julia)
-        end
-    catch
-        # The fast path uses Highlights internals; fall back to the public API
-        # if they change
-        try
-            return sprint(highlight, MIME("text/ansi"), code, :julia, _current_theme[]; context=context)
-        catch e
-            printstyled(stderr, "failed to highlight code, $e\n"; color=Base.warn_color())
-            return code
+            Highlights.highlight(io, MIME("text/ansi"), code, tree_sitter_julia_jll, _current_theme[])
         end
+    catch e
+        printstyled(stderr, "failed to highlight code, $e\n"; color=Base.warn_color())
+        return code
     end
 end
 
diff --git a/test/misc.jl b/test/misc.jl
index c19212f..2c758c2 100644
--- a/test/misc.jl
+++ b/test/misc.jl
@@ -478,3 +478,26 @@ end
     # the session survived: `fr` after the error still prints the locals
     @test occursin(r"y.*= .*2", out)
 end
+
+# Highlighting must work when the grammar jll is not a direct dep of the active
+# project (i.e. Debugger installed as an indirect dependency). An empty active
+# project reproduces that; `:julia` symbol lookup would fail there.
+@testset "highlighting when grammar jll is not a direct project dep" begin
+    prev_highlight = Debugger.config().highlight
+    Debugger.set_highlight(true)
+    old_project = Base.active_project()
+    try
+        mktempdir() do tmp
+            touch(joinpath(tmp, "Project.toml"))
+            Base.set_active_project(joinpath(tmp, "Project.toml"))
+            io = IOContext(IOBuffer(), :color => true)
+            out = Debugger.highlight_code("x = 1"; context=io)
+            # ANSI escapes mean it highlighted; the bug silently fell back to
+            # the un-highlighted source.
+            @test occursin("\e[", out)
+        end
+    finally
+        Base.set_active_project(old_project)
+        Debugger.set_highlight(prev_highlight)
+    end
+end

From bf3243b181cf2d82ad07dd6e953fd62df9534377 Mon Sep 17 00:00:00 2001
From: Oscar Smith <oscardssmith@gmail.com>
Date: Fri, 24 Jul 2026 11:04:16 -0400
Subject: [PATCH 2/4] bump Highlight compat

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index 19e08f8..ffe74aa 100644
--- a/Project.toml
+++ b/Project.toml
@@ -17,7 +17,7 @@ TerminalRegressionTests = {url = "https://github.com/JuliaDebug/TerminalRegressi
 
 [compat]
 CodeTracking = "2, 3"
-Highlights = "0.6"
+Highlights = "0.6.2"
 JuliaInterpreter = "0.10, 0.11"
 PrecompileTools = "1"
 TerminalRegressionTests = "0.3"

From e9658597f7d26a738d2de19d0ba77f7b8e267277 Mon Sep 17 00:00:00 2001
From: Oscar Smith <oscardssmith@gmail.com>
Date: Sat, 25 Jul 2026 12:19:32 -0400
Subject: [PATCH 3/4] remove source

---
 Project.toml | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/Project.toml b/Project.toml
index ffe74aa..77c8c86 100644
--- a/Project.toml
+++ b/Project.toml
@@ -12,9 +12,6 @@ PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
 tree_sitter_julia_jll = "52be201e-a5e9-5cfe-8bf2-2dc4b062171c"
 
-[sources]
-TerminalRegressionTests = {url = "https://github.com/JuliaDebug/TerminalRegressionTests.jl", rev = "675923307baa801cd32f5774b4b375723c650b54"}
-
 [compat]
 CodeTracking = "2, 3"
 Highlights = "0.6.2"

From 77b8d76185c50025fa717c4c052f009fc9bffc66 Mon Sep 17 00:00:00 2001
From: Oscar Smith <oscardssmith@gmail.com>
Date: Sat, 25 Jul 2026 12:59:27 -0400
Subject: [PATCH 4/4] fix ci

---
 .github/workflows/CI.yml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 3ad295b..82b8781 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -35,8 +35,6 @@ jobs:
           arch: ${{ matrix.arch }}
       - uses: julia-actions/cache@v3
       - uses: julia-actions/julia-buildpkg@v1
-      - name: Use TerminalRegressionTests Julia 1.12 support branch
-        run: julia --project=. --color=yes -e 'using Pkg; Pkg.add(Pkg.PackageSpec(url="https://github.com/JuliaDebug/TerminalRegressionTests.jl", rev="kc/terminal-1.12-support"))'
       - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1
       - uses: codecov/codecov-action@v7