Fix PixiBuilder.build() to fully install the pixi environment

Previously, the content-based code paths (pixi.toml, pyproject.toml,
environment.yml) wrote the manifest file but never ran `pixi install`,
so .pixi/envs/default was only created later, on demand, when the first
`pixi run` was invoked. The fix moves `pixi install` into
createEnvironment(), covering all build() exit paths uniformly.

Adds testBuildInstallsEnv() which asserts .pixi/envs/default exists
immediately after build() returns, before any service is launched.

To accommodate this change, WrapTest.testWrapPixi now needs to write a
valid pixi.toml instead of an empty one, since pixi install now happens
even when wrapping an existing environment, and it rejects empty
manifests. So we now write a minimal valid [workspace] declaration to
satisfy pixi install, and switch the finally-block cleanup to
FilePaths.deleteRecursively because pixi install creates a .pixi/ tree.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ctrueden

src/main/java/org/apposed/appose/builder/PixiBuilder.java

@@ -269,12 +269,23 @@ public Environment wrap(File envDir) throws BuildException {
 
 	// -- Helper methods --
 
-	private Environment createEnvironment(Pixi pixi, File envDir) {
-		String base = envDir.getAbsolutePath();
-		String envName = pixiEnvironment != null ? pixiEnvironment : "default";
+	private Environment createEnvironment(Pixi pixi, File envDir) throws IOException, InterruptedException {
 		// Check which manifest file exists (pyproject.toml takes precedence).
 		File manifestFile = new File(envDir, "pyproject.toml");
 		if (!manifestFile.exists()) manifestFile = new File(envDir, "pixi.toml");
+
+		// Ensure the pixi environment is fully installed.
+		List<String> installCmd = new ArrayList<>(Arrays.asList(
+				"install", "--manifest-path", manifestFile.getAbsolutePath()
+		));
+		if (pixiEnvironment != null) {
+			installCmd.add("--environment");
+			installCmd.add(pixiEnvironment);
+		}
+		pixi.exec(installCmd.toArray(new String[0]));
+
+		String base = envDir.getAbsolutePath();
+		String envName = pixiEnvironment != null ? pixiEnvironment : "default";
 		List<String> launchArgs = new ArrayList<>(Arrays.asList(
 				pixi.command, "run", "--manifest-path",
 				manifestFile.getAbsolutePath()

src/test/java/org/apposed/appose/builder/PixiBuilderTest.java

@@ -217,6 +217,27 @@ public void testPixiEnvironmentSelection() throws Exception {
 		cowsayAndAssert(env, "multi-env");
 	}
 
+	/**
+	 * Tests that {@link PixiBuilder#build()} fully installs the pixi environment,
+	 * i.e. that {@code .pixi/envs/default} exists after {@code build()} returns,
+	 * not only after the first {@code pixi run} invocation.
+	 */
+	@Test
+	public void testBuildInstallsEnv() throws Exception {
+		Environment env = Appose
+			.pixi("src/test/resources/envs/cowsay-pixi.toml")
+			.base("target/envs/pixi-build-installs-env")
+			.logDebug()
+			.rebuild();
+		// The default pixi environment directory must exist right after build(),
+		// before any service is launched. This was the bug: build() used to only
+		// write pixi.toml, leaving installation to the first pixi run invocation.
+		File envDir = new File(env.base(), ".pixi/envs/default");
+		assertTrue(envDir.isDirectory(),
+			".pixi/envs/default should exist after build(), but was missing: " + envDir);
+		cowsayAndAssert(env, "installed");
+	}
+
 	/** Tests building from a file:// URL to exercise URL support. */
 	@Test
 	public void testURLSupport() throws Exception {

src/test/java/org/apposed/appose/builder/WrapTest.java

@@ -35,7 +35,10 @@
 import org.apposed.appose.TestBase;
 import org.junit.jupiter.api.Test;
 
+import org.apposed.appose.util.FilePaths;
+
 import java.io.File;
+import java.io.FileWriter;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
@@ -53,7 +56,12 @@ public void testWrapPixi() throws Exception {
 		File pixiDir = new File("target/test-wrap-pixi");
 		pixiDir.mkdirs();
 		File pixiToml = new File(pixiDir, "pixi.toml");
-		pixiToml.createNewFile();
+		try (FileWriter w = new FileWriter(pixiToml)) {
+			w.write("[workspace]\n");
+			w.write("name = \"test-wrap-pixi\"\n");
+			w.write("channels = [\"conda-forge\"]\n");
+			w.write("platforms = [\"linux-64\", \"osx-64\", \"osx-arm64\", \"win-64\"]\n");
+		}
 
 		try {
 			Environment pixiEnv = Appose.wrap(pixiDir);
@@ -65,8 +73,7 @@ public void testWrapPixi() throws Exception {
 			assertTrue(pixiEnv.launchArgs().get(0).contains("pixi"),
 				"Pixi environment should use pixi launcher");
 		} finally {
-			pixiToml.delete();
-			pixiDir.delete();
+			FilePaths.deleteRecursively(pixiDir);
 		}
 	}