Use GzipChildStream again

....spawn-stream appears to be causing issues in the new nimrod data 
downloader

package-lock.json

@@ -328,11 +328,6 @@
 			"resolved": "https://registry.npmjs.org/shebang-regex/-/shebang-regex-3.0.0.tgz",
 			"integrity": "sha512-7++dFhtcx3353uBaq8DDR4NuxBetBzC7ZQOhmTQInHEd6bSrXdiEyzCvG07Z44UYdLShWUyXt5M/yhz8ekcb1A=="
 		},
-		"spawn-stream": {
-			"version": "1.0.2",
-			"resolved": "https://registry.npmjs.org/spawn-stream/-/spawn-stream-1.0.2.tgz",
-			"integrity": "sha1-W9VkENXISo7N6y5jEnEWytkQUMs="
-		},
 		"string-to-arraybuffer": {
 			"version": "1.0.2",
 			"resolved": "https://registry.npmjs.org/string-to-arraybuffer/-/string-to-arraybuffer-1.0.2.tgz",

package.json

@@ -37,7 +37,6 @@
 		"chroma-js": "^2.1.0",
 		"image-encode": "^1.3.0",
 		"nexline": "^1.2.1",
-		"spawn-stream": "^1.0.2",
 		"terrain50": "^1.8.2"
 	},
 	"bin": {

src/Helpers/GzipChildProcess.mjs

@@ -0,0 +1,61 @@
+"use strict";
+
+import EventEmitter from 'events';
+import child_process from 'child_process';
+import { end_safe } from '../../helpers/StreamHelpers.mjs';
+
+/**
+ * Spawns and manages a gzip child process.
+ * @deprecated Use spawn-stream instead
+ * @extends EventEmitter
+ */
+class GzipChildProcess extends EventEmitter {
+	get stdin() { return this.child_process.stdin; }
+	get stdout() { return this.child_process.stdout; }
+	get stderr() { return this.child_process.stderr; }
+	
+	constructor(auto_start = true) {
+		super();
+		
+		this.child_process = null;
+		
+		this.has_exited = false;
+		
+		if(auto_start)
+			this.start();
+	}
+	
+	start() {
+		if(this.child_process != null)
+			throw new Error("Invalid Operation: Can't start the child process, since it's already been started.");
+		
+		this.child_process = child_process.spawn(
+			"gzip", [], {
+				// Pipe stdin + stdout; send error to the parent process
+				stdio: [ "pipe", "pipe", "inherit" ]
+			}
+		);
+		this.child_process.on("exit", () => {
+			this.has_exited = true;
+			this.emit("exit");
+		});
+		// FUTURE: Perhaps just throwing the error would be a better choice?
+		this.child_process.on("error", (error) => {
+			this.emit("error", error);
+		});
+		
+	}
+	
+	/**
+	 * Returns a Promise that resolves when the gzip process exits.
+	 * If the gzip child process has already exited, then it resolves immediately.
+	 * @return	{Promise}
+	 */
+	async end_gracefully() {
+		await end_safe(this.stdin);
+		if(this.has_exited) return;
+		await EventEmitter.once(this, "exit");
+	}
+}
+
+export default GzipChildProcess;

src/Subcommands/split/index.mjs

@@ -9,6 +9,9 @@ import SpawnStream from 'spawn-stream';
 import a from '../../Helpers/Ansi.mjs';
 import l from '../../Helpers/Log.mjs';
 
+import GzipChildProcess from '../../Helpers/GzipChildProcess.mjs';
+import { end_safe } from '../../Helpers/StreamHelpers.mjs';
+
 export default async function(settings) {
 	// 1: Parse settings
 	let stream_in = process.stdin;
@@ -39,15 +42,20 @@ export default async function(settings) {
 		
 		// Create the output stream
 		let stream_out = fs.createWriteStream(output_filename),
-			stream_gzip = null;
+			gzip = null;
 		if(!settings.cli.no_gzip) {
-			stream_gzip = SpawnStream("gzip");
-			stream_gzip.pipe(stream_out);
+			gzip = new GzipChildProcess();
+			gzip.stdout.pipe(stream_out);
 		}
 		
+		let init_stream = stream_out;
+		if(gzip !== null) init_stream = gzip.stdin;
 		
 		// Write it to the output
-		await next.serialise(stream_gzip || stream_out, true);
+		await next.serialise(init_stream || stream_out, false);
+		
+		if(gzip !== null) await gzip.end_gracefully();
+		await end_safe(stream_out);
 		
 		// Update the user
 		l.log(`Written ${i+1} objects so far`);