Fix Permission denied error when building installed packages

CalcPi.jl/deps/build.jl

@@ -24,16 +24,37 @@ if isdir(DEV_DIR)
     # Always copy to libcalcpi_rs.<ext> in deps/ for consistency
     cp(libcalcpi_path, joinpath(@__DIR__, "libcalcpi_rs.$(dlext)"); force=true)
 
-    cd(joinpath(dirname(@__DIR__), "utils")) do
-        run(`$(Base.julia_cmd()) --project generate_C_API.jl`)
+    # Generate C_API.jl in a temporary directory first, then copy to the appropriate location
+    # This handles the case where the package is installed and src/ is read-only
+    package_dir = dirname(@__DIR__)
+    src_dir = joinpath(package_dir, "src")
+    temp_output_dir = mktempdir()
+
+    cd(joinpath(package_dir, "utils")) do
+        run(`$(Base.julia_cmd()) --project generate_C_API.jl --output-dir $temp_output_dir`)
     end
 
-    # Remove CEnum import if not needed (post-processing)
-    c_api_path = joinpath(dirname(@__DIR__), "src", "C_API.jl")
-    if isfile(c_api_path)
-        content = read(c_api_path, String)
-        # Remove CEnum import if present
-        content = replace(content, r"using CEnum: CEnum, @cenum\n\n" => "")
-        write(c_api_path, content)
+    # Copy generated file to src/ if writable
+    temp_c_api_path = joinpath(temp_output_dir, "C_API.jl")
+    if isfile(temp_c_api_path)
+        c_api_path = joinpath(src_dir, "C_API.jl")
+        # Check if src/ is writable by testing write access
+        try
+            content = read(temp_c_api_path, String)
+            # Remove CEnum import if not needed (post-processing)
+            content = replace(content, r"using CEnum: CEnum, @cenum\n\n" => "")
+            # Try to write to src/
+            open(c_api_path, "w") do f
+                write(f, content)
+            end
+            println("Generated C_API.jl in src/")
+        catch e
+            # If src/ is read-only (e.g., installed package), skip writing
+            # The existing C_API.jl in the package should be used
+            println("Warning: Cannot write to src/ (package may be installed). Using existing C_API.jl.")
+        end
+        rm(temp_output_dir; recursive=true)
+    else
+        error("Failed to generate C_API.jl")
     end
 end

CalcPi.jl/utils/generate_C_API.jl

@@ -11,28 +11,46 @@ function print_help()
     println()
     println("Options:")
     println("  --calcpi-rs-dir PATH    Specify the calcpi-rs directory path")
+    println("  --output-dir PATH       Specify the output directory for C_API.jl")
     println("  --help, -h              Show this help message")
     println()
     println("Examples:")
     println("  julia generate_C_API.jl --calcpi-rs-dir /path/to/calcpi-rs")
+    println("  julia generate_C_API.jl --output-dir /path/to/output")
     println()
     println("Default: Uses ../deps/calcpi-rs relative to this script")
+    println("         Output goes to ../src/C_API.jl relative to this script")
 end
 
 # Parse command line arguments
 calcpi_rs_dir = nothing
-for (i, arg) in enumerate(ARGS)
+output_dir = nothing
+i = 1
+while i <= length(ARGS)
+    arg = ARGS[i]
     if arg == "--help" || arg == "-h"
         print_help()
         exit(0)
     elseif arg == "--calcpi-rs-dir"
         if i + 1 <= length(ARGS)
             global calcpi_rs_dir
             calcpi_rs_dir = ARGS[i + 1]
+            i += 2
         else
             println("Error: --calcpi-rs-dir requires a path argument")
             exit(1)
         end
+    elseif arg == "--output-dir"
+        if i + 1 <= length(ARGS)
+            global output_dir
+            output_dir = ARGS[i + 1]
+            i += 2
+        else
+            println("Error: --output-dir requires a path argument")
+            exit(1)
+        end
+    else
+        i += 1
     end
 end
 
@@ -74,6 +92,16 @@ else
     options = Dict{String,Any}()
 end
 
+# Override output path if specified
+if output_dir !== nothing
+    output_dir = normpath(abspath(output_dir))
+    if !isdir(output_dir)
+        mkpath(output_dir)
+    end
+    options["output_file_path"] = joinpath(output_dir, "C_API.jl")
+    println("Output directory: $output_dir")
+end
+
 # add compiler flags, e.g. "-DXXXXXXXXX"
 args = get_default_args()
 push!(args, "-I$include_dir")

run.sh

@@ -0,0 +1 @@
+julia -e 'using Pkg; Pkg.activate(temp=true); Pkg.add(url="git@github.com:AtelierArith/RustToolChainExamples.jl.git", subdir="CalcPi.jl"); Pkg.test("CalcPi")'