replace backslashes in user-specified project path

Author: jkrumbiegel

src/execute/julia.ts

@@ -34,7 +34,7 @@ import {
 } from "../config/format.ts";
 import { resourcePath } from "../core/resources.ts";
 import { quartoRuntimeDir } from "../core/appdirs.ts";
-import { normalizePath } from "../core/path.ts";
+import { normalizePath, pathWithForwardSlashes } from "../core/path.ts";
 import { isInteractiveSession } from "../core/platform.ts";
 import { runningInCI } from "../core/ci-info.ts";
 import { sleep } from "../core/async.ts";
@@ -271,6 +271,7 @@ async function startOrReuseJuliaServer(
       await ensureQuartoNotebookRunnerEnvironment(options);
       juliaProject = juliaRuntimeDir();
     } else {
+      juliaProject = pathWithForwardSlashes(juliaProject);
       trace(
         options,
         `Custom julia project set via QUARTO_JULIA_PROJECT="${juliaProject}". Checking if QuartoNotebookRunner can be loaded.`,