diff --git a/packages/processor/processor.js b/packages/processor/processor.js
index a547cdc1d..9a31d75cf 100644
--- a/packages/processor/processor.js
+++ b/packages/processor/processor.js
@@ -33,50 +33,49 @@ function params(processor, args) {
 
 class Processor {
     constructor(opts) {
-        /* eslint max-statements: [ "warn", 20 ] */
-        this._options = Object.assign(
+        /* eslint max-statements: [ "warn", 25 ] */
+        const options = Object.assign(
             Object.create(null),
             {
-                cwd     : process.cwd(),
-                map     : false,
-                rewrite : true,
-                verbose : false,
+                cwd       : process.cwd(),
+                map       : false,
+                rewrite   : true,
+                verbose   : false,
+                resolvers : [],
             },
             opts
         );
 
-        if(!path.isAbsolute(this._options.cwd)) {
-            this._options.cwd = path.resolve(this._options.cwd);
-        }
+        this._options = options;
 
-        if(typeof this._options.namer === "string") {
-            this._options.namer = require(this._options.namer)();
+        if(!path.isAbsolute(options.cwd)) {
+            options.cwd = path.resolve(options.cwd);
         }
 
-        if(typeof this._options.namer !== "function") {
-            this._options.namer = (file, selector) =>
-                `mc${slug(relative(this._options.cwd, file))}_${selector}`;
+        if(typeof options.namer === "string") {
+            options.namer = require(options.namer)();
         }
 
-        if(!Array.isArray(this._options.resolvers)) {
-            this._options.resolvers = [];
+        if(typeof options.namer !== "function") {
+            options.namer = (file, selector) =>
+                `mc${slug(relative(options.cwd, file))}_${selector}`;
         }
 
-        this._log = this._options.verbose ?
+        this._log = options.verbose ?
             // eslint-disable-next-line no-console
             console.log.bind(console, "[processor]") :
             // eslint-disable-next-line no-empty-function
             () => {};
 
-        this._resolve = resolve.resolvers(this._options.resolvers);
+        this._resolve = resolve.resolvers(options.resolvers);
 
-        this._absolute = (file) => (path.isAbsolute(file) ? file : path.join(this._options.cwd, file));
+        this._absolute = (file) => (path.isAbsolute(file) ? file : path.join(options.cwd, file));
 
         this._files = Object.create(null);
         this._graph = new Graph();
 
         this._before = postcss([
-            ...(this._options.before || []),
+            ...(options.before || []),
             require("./plugins/values-local.js"),
             require("./plugins/values-export.js"),
             require("./plugins/values-replace.js"),
@@ -93,17 +92,17 @@ class Processor {
             require("./plugins/externals.js"),
             require("./plugins/composition.js"),
             require("./plugins/keyframes.js"),
-            ...(this._options.processing || []),
+            ...(options.processing || []),
         ]);
 
-        this._after = postcss(this._options.after || [ noop ]);
+        this._after = postcss(options.after || [ noop ]);
 
         // Add postcss-url to the afters if requested
-        if(this._options.rewrite) {
-            this._after.use(require("postcss-url")(this._options.rewrite));
+        if(options.rewrite) {
+            this._after.use(require("postcss-url")(options.rewrite));
         }
 
-        this._done = postcss(this._options.done || [ noop ]);
+        this._done = postcss(options.done || [ noop ]);
     }
 
     // Add a file on disk to the dependency graph
diff --git a/packages/processor/test/__snapshots__/options.test.js.snap b/packages/processor/test/__snapshots__/options.test.js.snap
index c7565399b..fdc00ee0c 100644
--- a/packages/processor/test/__snapshots__/options.test.js.snap
+++ b/packages/processor/test/__snapshots__/options.test.js.snap
@@ -74,6 +74,76 @@ exports[`/processor.js options lifecycle options processing should run sync post
 a {}"
 `;
 
+exports[`/processor.js options lifecycle options verbose should output debugging messages when verbose mode is enabled 1`] = `
+Array [
+  Array [
+    "[processor]",
+    "file()",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "string()",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/processor/test/specimens/folder/folder.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/processor/test/specimens/folder/folder.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/processor/test/specimens/local.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/processor/test/specimens/local.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "string() done",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "string()",
+    "packages/processor/test/specimens/string.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/processor/test/specimens/string.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/processor/test/specimens/string.css",
+  ],
+  Array [
+    "[processor]",
+    "string() done",
+    "packages/processor/test/specimens/string.css",
+  ],
+]
+`;
+
 exports[`/processor.js options map should generate external source maps 1`] = `
 "/* packages/processor/test/specimens/folder/folder.css */
 .folder { margin: 2px; }
diff --git a/packages/processor/test/options.test.js b/packages/processor/test/options.test.js
index 5f69ac0bb..f359c956d 100644
--- a/packages/processor/test/options.test.js
+++ b/packages/processor/test/options.test.js
@@ -5,6 +5,7 @@ const path = require("path");
 const dedent   = require("dedent");
 const namer    = require("@modular-css/test-utils/namer.js");
 const relative = require("@modular-css/test-utils/relative.js");
+const logs     = require("@modular-css/test-utils/logs.js");
 
 const Processor = require("../processor.js");
 
@@ -370,6 +371,27 @@ describe("/processor.js", () => {
                     .then((result) => expect(result.css).toMatchSnapshot());
                 });
             });
+
+            describe("verbose", () => {
+                it("should output debugging messages when verbose mode is enabled", async () => {
+                    const { logSnapshot } = logs();
+
+                    const processor = new Processor({
+                        namer,
+                        verbose : true,
+                    });
+                    
+                    await processor.file("./packages/processor/test/specimens/start.css");
+                    await processor.string(
+                        "packages/processor/test/specimens/string.css",
+                        ".foo { color: fuschia; }"
+                    );
+
+                    await processor.output();
+
+                    logSnapshot();
+                });
+            });
         });
     });
 });
diff --git a/packages/rollup/rollup.js b/packages/rollup/rollup.js
index 4cde5c8b6..8eadd4fca 100644
--- a/packages/rollup/rollup.js
+++ b/packages/rollup/rollup.js
@@ -35,11 +35,15 @@ module.exports = function(opts) {
         namedExports : true,
         styleExport  : false,
         dev          : false,
+        verbose      : false,
     }, opts);
         
     const filter = utils.createFilter(options.include, options.exclude);
 
-    const { styleExport, done, map, dev } = options;
+    const { styleExport, done, map, dev, verbose } = options;
+
+    // eslint-disable-next-line no-console, no-empty-function
+    const log = verbose ? console.log.bind(console, "[rollup]") : () => {};
 
     if(typeof map === "undefined") {
         // Sourcemaps don't make much sense in styleExport mode
@@ -53,6 +57,8 @@ module.exports = function(opts) {
         name : "@modular-css/rollup",
 
         buildStart() {
+            log("build start");
+
             // done lifecycle won't ever be called on per-component styles since
             // it only happens at bundle compilation time
             // Need to do this on buildStart so it has access to this.warn() o_O
@@ -68,6 +74,8 @@ module.exports = function(opts) {
                 return;
             }
 
+            log("file changed", file);
+
             processor.dependents(file).forEach((dep) =>
                 processor.remove(dep)
             );
@@ -80,6 +88,8 @@ module.exports = function(opts) {
                 return null;
             }
 
+            log("transform", id);
+
             const { details, exports } = await processor.string(id, code);
 
             const exported = output.join(exports);
@@ -226,6 +236,8 @@ module.exports = function(opts) {
                 .map(async ({ base, name, css }, idx) => {
                     const id = this.emitAsset(`${base}.css`);
 
+                    log("css output", id);
+
                     const result = await processor.output({
                         to : to.replace(/\[(name|extname)\]/g, (match, field) =>
                             (field === "name" ? name : ".css")
@@ -240,11 +252,17 @@ module.exports = function(opts) {
                     if(options.json && idx === 0) {
                         const file = typeof options.json === "string" ? options.json : "exports.json";
 
+                        log("json output", file);
+                        
                         this.emitAsset(file, JSON.stringify(result.compositions, null, 4));
                     }
 
                     if(result.map) {
-                        this.emitAsset(`${base}.css.map`, result.map.toString());
+                        const file = `${base}.css.map`;
+
+                        log("map output", file);
+
+                        this.emitAsset(file, result.map.toString());
                     }
                 })
             );
diff --git a/packages/rollup/test/__snapshots__/rollup.test.js.snap b/packages/rollup/test/__snapshots__/rollup.test.js.snap
index b8c5d5feb..542a85e45 100644
--- a/packages/rollup/test/__snapshots__/rollup.test.js.snap
+++ b/packages/rollup/test/__snapshots__/rollup.test.js.snap
@@ -110,6 +110,110 @@ exports[`/rollup.js should handle assetFileNames being undefined 1`] = `
 "
 `;
 
+exports[`/rollup.js should log in verbose mode 1`] = `
+Array [
+  Array [
+    "[rollup]",
+    "build start",
+  ],
+  Array [
+    "[rollup]",
+    "transform",
+    "packages/rollup/test/specimens/simple.css",
+  ],
+  Array [
+    "[processor]",
+    "string()",
+    "packages/rollup/test/specimens/simple.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/rollup/test/specimens/simple.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/rollup/test/specimens/simple.css",
+  ],
+  Array [
+    "[processor]",
+    "string() done",
+    "packages/rollup/test/specimens/simple.css",
+  ],
+  Array [
+    "[rollup]",
+    "css output",
+    "40a365e7",
+  ],
+  Array [
+    "[processor]",
+    "file()",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "string()",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/processor/test/specimens/folder/folder.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/processor/test/specimens/folder/folder.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/processor/test/specimens/local.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/processor/test/specimens/local.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "string() done",
+    "packages/processor/test/specimens/start.css",
+  ],
+  Array [
+    "[processor]",
+    "string()",
+    "packages/processor/test/specimens/string.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/processor/test/specimens/string.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/processor/test/specimens/string.css",
+  ],
+  Array [
+    "[processor]",
+    "string() done",
+    "packages/processor/test/specimens/string.css",
+  ],
+]
+`;
+
 exports[`/rollup.js should not output sourcemaps when they are disabled 1`] = `
 "/* packages/rollup/test/specimens/simple.css */
 .fooga {
diff --git a/packages/rollup/test/rollup.test.js b/packages/rollup/test/rollup.test.js
index 995cc08f4..8874b3ed9 100644
--- a/packages/rollup/test/rollup.test.js
+++ b/packages/rollup/test/rollup.test.js
@@ -6,10 +6,11 @@ const { rollup } = require("rollup");
 const dedent = require("dedent");
 const shell = require("shelljs");
 
-const read = require("@modular-css/test-utils/read.js")(__dirname);
+const read   = require("@modular-css/test-utils/read.js")(__dirname);
 const exists = require("@modular-css/test-utils/exists.js")(__dirname);
 const prefix = require("@modular-css/test-utils/prefix.js")(__dirname);
-const namer = require("@modular-css/test-utils/namer.js");
+const namer  = require("@modular-css/test-utils/namer.js");
+const logs   = require("@modular-css/test-utils/logs.js");
 
 const Processor = require("@modular-css/processor");
 
@@ -215,9 +216,7 @@ describe("/rollup.js", () => {
     });
 
     it("should warn that styleExport and done aren't compatible", async () => {
-        const spy = jest.spyOn(global.console, "warn");
-
-        spy.mockImplementation(() => { /* NO-OP */ });
+        const { logSnapshot } = logs("warn");
         
         await rollup({
             input   : require.resolve("./specimens/style-export.js"),
@@ -232,8 +231,7 @@ describe("/rollup.js", () => {
             ],
         });
 
-        expect(spy).toHaveBeenCalled();
-        expect(spy.mock.calls).toMatchSnapshot();
+        logSnapshot();
     });
 
     it("should generate external source maps", async () => {
@@ -453,6 +451,40 @@ describe("/rollup.js", () => {
         expect(result.code).toMatchSnapshot();
     });
 
+    it("should log in verbose mode", async () => {
+        const { logSnapshot } = logs();
+
+        const bundle = await rollup({
+            input   : require.resolve("./specimens/simple.js"),
+            plugins : [
+                plugin({
+                    namer,
+                    verbose : true,
+                }),
+            ],
+        });
+
+        await bundle.generate({
+            format,
+            assetFileNames,
+        });
+        
+        const processor = new Processor({
+            namer,
+            verbose : true,
+        });
+
+        await processor.file("./packages/processor/test/specimens/start.css");
+        await processor.string(
+            "packages/processor/test/specimens/string.css",
+            ".foo { color: fuschia; }"
+        );
+
+        await processor.output();
+
+        logSnapshot();
+    });
+
     describe("errors", () => {
         function checkError(err) {
             expect(err.toString()).toMatch("error-plugin:");
diff --git a/packages/svelte/src/markup.js b/packages/svelte/src/markup.js
index 89f00d36e..afe5262e5 100644
--- a/packages/svelte/src/markup.js
+++ b/packages/svelte/src/markup.js
@@ -10,11 +10,13 @@ const scriptRegex = /<script[\S\s]*?>([\S\s]*?)<\/script>/im;
 const linkRegex = /<link\b[^<>]*?\bhref=\s*(?:"([^"]+)"|'([^']+)'|([^>\s]+))[^>]*>/im;
 const missedRegex = /css\.\w+/gim;
 
-function updateCss({ processor, content, result, filename }) {
+function updateCss({ processor, log, content, result, filename }) {
     const exported = result.files[result.file].exports;
     const keys = Object.keys(exported);
     let code = content;
     
+    log("updating css references", filename, JSON.stringify(keys));
+
     if(keys.length) {
         const selectors = keys.join("|");
 
@@ -54,12 +56,14 @@ function updateCss({ processor, content, result, filename }) {
     };
 }
 
-async function extractLink({ processor, content, filename, link }) {
+async function extractLink({ processor, log, content, filename, link }) {
     // This looks weird, but it's to support multiple types of quotation marks
     const href = link[1] || link[2] || link[3];
     
     const external = resolve(path.dirname(filename), href);
 
+    log("extract <link>", filename, external);
+
     // Remove any files that've already been encountered, they should be re-processed
     if(external in processor.files) {
         [ ...processor.dependents(external), external ].forEach((file) => processor.remove(file));
@@ -94,13 +98,16 @@ async function extractLink({ processor, content, filename, link }) {
 
     return updateCss({
         processor,
+        log,
         content,
         result,
         filename : href,
     });
 }
 
-async function extractStyle({ processor, content, filename, style }) {
+async function extractStyle({ processor, log, content, filename, style }) {
+    log("extract <style>", filename);
+    
     const result = await processor.string(
         filename,
         style[1]
@@ -108,16 +115,20 @@ async function extractStyle({ processor, content, filename, style }) {
 
     return updateCss({
         processor,
+        log,
         content,
         result,
         filename : "<style>",
     });
 }
 
-module.exports = (processor) => ({ content, filename }) => {
+module.exports = (processor, config) => ({ content, filename }) => {
     const link = content.match(linkRegex);
     const style = content.match(styleRegex);
 
+    // eslint-disable-next-line no-console, no-empty-function
+    const log = config.verbose ? console.log.bind(console, "[svelte]") : () => {};
+
     if(link && style) {
         throw new Error("@modular-css/svelte: use <style> OR <link>, but not both");
     }
@@ -125,6 +136,7 @@ module.exports = (processor) => ({ content, filename }) => {
     if(style) {
         return extractStyle({
             processor,
+            log,
             content,
             filename,
             style,
@@ -134,6 +146,7 @@ module.exports = (processor) => ({ content, filename }) => {
     if(link) {
         return extractLink({
             processor,
+            log,
             content,
             filename,
             link,
diff --git a/packages/svelte/svelte.js b/packages/svelte/svelte.js
index 9f1edc0b6..feff51856 100644
--- a/packages/svelte/svelte.js
+++ b/packages/svelte/svelte.js
@@ -8,7 +8,10 @@ const style = require("./src/style.js");
 module.exports = function(args) {
     const config = Object.assign(
         Object.create(null),
-        { strict : false },
+        {
+            strict  : false,
+            verbose : false,
+        },
         args
     );
 
@@ -18,7 +21,7 @@ module.exports = function(args) {
         processor,
 
         preprocess : {
-            markup : markup(processor),
+            markup : markup(processor, config),
             style,
         },
     };
diff --git a/packages/svelte/test/__snapshots__/svelte.test.js.snap b/packages/svelte/test/__snapshots__/svelte.test.js.snap
index dc0b9aa05..ff40e4d03 100644
--- a/packages/svelte/test/__snapshots__/svelte.test.js.snap
+++ b/packages/svelte/test/__snapshots__/svelte.test.js.snap
@@ -364,4 +364,122 @@ exports[`/svelte.js should remove files before reprocessing in case they changed
 }"
 `;
 
+exports[`/svelte.js should support verbose output: "<link>" 1`] = `
+Array [
+  Array [
+    "[svelte]",
+    "extract <link>",
+    "packages/svelte/test/specimens/external.html",
+    "packages/svelte/test/specimens/external.css",
+  ],
+  Array [
+    "[processor]",
+    "file()",
+    "packages/svelte/test/specimens/external.css",
+  ],
+  Array [
+    "[processor]",
+    "string()",
+    "packages/svelte/test/specimens/external.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/svelte/test/specimens/simple.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/svelte/test/specimens/simple.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/svelte/test/specimens/dependencies.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/svelte/test/specimens/dependencies.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/svelte/test/specimens/external.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/svelte/test/specimens/external.css",
+  ],
+  Array [
+    "[processor]",
+    "string() done",
+    "packages/svelte/test/specimens/external.css",
+  ],
+  Array [
+    "[svelte]",
+    "updating css references",
+    "./external.css",
+    "[\\"flex\\",\\"wrapper\\",\\"hd\\",\\"bd\\",\\"text\\",\\"active\\"]",
+  ],
+]
+`;
+
+exports[`/svelte.js should support verbose output: "<style>" 1`] = `
+Array [
+  Array [
+    "[svelte]",
+    "extract <style>",
+    "packages/svelte/test/specimens/style.html",
+  ],
+  Array [
+    "[processor]",
+    "string()",
+    "packages/svelte/test/specimens/style.html",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/svelte/test/specimens/simple.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/svelte/test/specimens/simple.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/svelte/test/specimens/dependencies.css",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/svelte/test/specimens/dependencies.css",
+  ],
+  Array [
+    "[processor]",
+    "processing",
+    "packages/svelte/test/specimens/style.html",
+  ],
+  Array [
+    "[processor]",
+    "processed",
+    "packages/svelte/test/specimens/style.html",
+  ],
+  Array [
+    "[processor]",
+    "string() done",
+    "packages/svelte/test/specimens/style.html",
+  ],
+  Array [
+    "[svelte]",
+    "updating css references",
+    "<style>",
+    "[\\"flex\\",\\"wrapper\\",\\"hd\\",\\"bd\\",\\"text\\",\\"active\\"]",
+  ],
+]
+`;
+
 exports[`/svelte.js should throw on both <style> and <link> in one file 1`] = `"@modular-css/svelte: use <style> OR <link>, but not both"`;
diff --git a/packages/svelte/test/svelte.test.js b/packages/svelte/test/svelte.test.js
index eb7922790..5e5e0286d 100644
--- a/packages/svelte/test/svelte.test.js
+++ b/packages/svelte/test/svelte.test.js
@@ -7,6 +7,7 @@ const svelte = require("svelte");
 const dedent = require("dedent");
 
 const namer = require("@modular-css/test-utils/namer.js");
+const logs  = require("@modular-css/test-utils/logs.js");
     
 const plugin = require("../svelte.js");
 
@@ -32,10 +33,10 @@ describe("/svelte.js", () => {
     });
 
     it.each`
-        specimen | title
-        ${"external.html"} | ${"no script"}
-        ${"external-script.html"} | ${"existing script"}
-        ${"external-single.html"} | ${"single quotes"}
+        specimen                    | title
+        ${"external.html"}          | ${"no script"}
+        ${"external-script.html"}   | ${"existing script"}
+        ${"external-single.html"}   | ${"single quotes"}
         ${"external-unquoted.html"} | ${"unquoted"}
     `("should extract CSS from a <link> tag ($title)", async ({ specimen }) => {
         const filename = require.resolve(`./specimens/${specimen}`);
@@ -178,4 +179,28 @@ describe("/svelte.js", () => {
 
         expect(output.css).toMatchSnapshot();
     });
+
+    it.each`
+        title        | specimen
+        ${"<style>"} | ${"style.html"}
+        ${"<link>"}  | ${"external.html"}
+    `("should support verbose output: $title", async ({ specimen }) => {
+        const { logSnapshot } = logs();
+        
+        const filename = require.resolve(`./specimens/${specimen}`);
+        
+        const { processor, preprocess } = plugin({
+            namer,
+            verbose : true,
+        });
+
+        await svelte.preprocess(
+            fs.readFileSync(filename, "utf8"),
+            Object.assign({}, preprocess, { filename })
+        );
+
+        await processor.output();
+
+        logSnapshot();
+    });
 });
diff --git a/packages/test-utils/logs.js b/packages/test-utils/logs.js
new file mode 100644
index 000000000..68363dd9b
--- /dev/null
+++ b/packages/test-utils/logs.js
@@ -0,0 +1,28 @@
+"use strict";
+
+const path = require("path");
+
+const relative = require("./relative.js");
+
+module.exports = (method = "log") => {
+    const spy = jest.spyOn(global.console, method);
+
+    spy.mockImplementation(() => { /* NO-OP */ });
+
+    return {
+        spy,
+
+        logSnapshot() {
+            expect(spy).toHaveBeenCalled();
+
+            const calls = spy.mock.calls.map((call) =>
+                call.map((arg) => (path.isAbsolute(arg) ?
+                    relative([ arg ])[0] :
+                    arg
+                ))
+            );
+
+            expect(calls).toMatchSnapshot();
+        },
+    };
+};