diff --git a/src/commands.ts b/src/commands.ts
index 36cc8cb..99dde41 100644
--- a/src/commands.ts
+++ b/src/commands.ts
@@ -48,7 +48,7 @@ import * as humanise from './humanise';
 import { partition } from './util';
 import { toFossilUri } from './uri';
 import { FossilPreviewManager } from './preview';
-import type { FossilCWD, FossilExecutable } from './fossilExecutable';
+import type { FossilCWD, FossilExecutable, Reason } from './fossilExecutable';
 
 import { localize } from './main';
 import type { Credentials } from './gitExport';
@@ -196,7 +196,7 @@ export class CommandCenter {
 
     @command(Inline.Repository)
     async refresh(repository: Repository): Promise<void> {
-        await repository.status('forced refresh');
+        await repository.status('forced refresh' as Reason);
     }
 
     @command()
diff --git a/src/fossilExecutable.ts b/src/fossilExecutable.ts
index 61d7f6a..4d02d65 100644
--- a/src/fossilExecutable.ts
+++ b/src/fossilExecutable.ts
@@ -19,6 +19,7 @@ export type FossilStdOut = Distinct<
     'raw fossil stdout' | 'fossil status stdout' | 'RenderedHTML'
 >;
 export type FossilStdErr = Distinct<string, 'raw fossil stderr'>;
+export type Reason = Distinct<string, 'exec reason'> | undefined;
 
 /** cwd for executing fossil */
 export type FossilCWD =
@@ -185,7 +186,7 @@ export class FossilExecutable {
         fossilCwd: FossilCWD,
         args: FossilArgs
     ): Promise<Buffer | undefined> {
-        const res = await this._loggingExec(args, '', { cwd: fossilCwd });
+        const res = await this._loggingExec(args, { cwd: fossilCwd });
         if (!res.exitCode) {
             return res.stdout;
         }
@@ -295,13 +296,13 @@ export class FossilExecutable {
 
     private async _loggingExec(
         args: FossilArgs,
-        reason: string,
-        options: FossilSpawnOptions
+        options: FossilSpawnOptions,
+        reason?: Reason
     ) {
         const startTimeHR = process.hrtime();
         const waitAndLog = (timeout: number): ReturnType<typeof setTimeout> => {
             return setTimeout(() => {
-                this.logArgs(args, reason, 'still running');
+                this.logArgs(args, 'still running', reason);
                 logTimeout = waitAndLog(timeout * 4);
             }, timeout);
         };
@@ -312,8 +313,8 @@ export class FossilExecutable {
         const durationHR = process.hrtime(startTimeHR);
         this.logArgs(
             args,
-            reason,
-            `${Math.floor(msFromHighResTime(durationHR))}ms`
+            `${Math.floor(msFromHighResTime(durationHR))}ms`,
+            reason
         );
         return resultRaw;
     }
@@ -321,13 +322,17 @@ export class FossilExecutable {
     public async exec(
         cwd: FossilCWD,
         args: FossilArgs,
-        reason = '',
+        reason?: Reason,
         options: Omit<FossilSpawnOptions, 'cwd'> = {} as const
     ): Promise<ExecResult> {
-        const resultRaw = await this._loggingExec(args, reason, {
-            cwd,
-            ...options,
-        });
+        const resultRaw = await this._loggingExec(
+            args,
+            {
+                cwd,
+                ...options,
+            },
+            reason
+        );
         const result: ExecResult = {
             ...resultRaw,
             stdout: resultRaw.stdout.toString('utf8') as FossilStdOut,
@@ -388,7 +393,7 @@ export class FossilExecutable {
     private log(output: string): void {
         this.outputChannel.info(output);
     }
-    private logArgs(args: FossilArgs, reason: string, info: string): void {
+    private logArgs(args: FossilArgs, info: string, reason: Reason): void {
         if (args[0] == 'clone') {
             // replace password with 9 asterisks
             args = [...args];
diff --git a/src/model.ts b/src/model.ts
index 8d8eb3b..119af24 100644
--- a/src/model.ts
+++ b/src/model.ts
@@ -19,7 +19,7 @@ import {
     commands,
     ConfigurationChangeEvent,
 } from 'vscode';
-import type { FossilExecutable } from './fossilExecutable';
+import type { FossilExecutable, Reason } from './fossilExecutable';
 import { anyEvent, filterEvent, dispose, eventToPromise } from './util';
 import { memoize, debounce, sequentialize } from './decorators';
 import * as path from 'path';
@@ -343,7 +343,9 @@ export class Model implements Disposable {
         for (const { oldUri, newUri } of e.files) {
             const repository = this.getRepository(oldUri);
             if (repository) {
-                await repository.updateModelState('file rename event');
+                await repository.updateModelState(
+                    'file rename event' as Reason
+                );
                 if (
                     repository.isInAnyGroup(oldUri) ||
                     repository.isDirInAnyGroup(oldUri)
diff --git a/src/openedRepository.ts b/src/openedRepository.ts
index 8e3f3e6..9b4648d 100644
--- a/src/openedRepository.ts
+++ b/src/openedRepository.ts
@@ -15,6 +15,7 @@ import {
     FossilSpawnOptions,
     FossilArgs,
     ExecResult,
+    Reason,
 } from './fossilExecutable';
 import { NewBranchOptions } from './interaction';
 import { FossilCWD } from './fossilExecutable';
@@ -205,7 +206,7 @@ export class OpenedRepository {
         const result = await executable.exec(
             cwd,
             ['info'],
-            `getting root for '${anypath}'`
+            `getting root for '${anypath}'` as Reason
         );
         const root = result.stdout.match(/local-root:\s*(.+)\/\s/);
         if (root) {
@@ -216,7 +217,7 @@ export class OpenedRepository {
 
     async exec(
         args: FossilArgs,
-        reason = '',
+        reason?: Reason,
         options: Omit<FossilSpawnOptions, 'cwd'> = {} as const
     ): Promise<ExecResult> {
         return this.executable.exec(this.root, args, reason, options);
@@ -539,7 +540,7 @@ export class OpenedRepository {
 
     /** Report the change status of files in the current checkout */
     @throttle
-    async getStatus(reason: string): Promise<ExecResult> {
+    async getStatus(reason: Reason): Promise<ExecResult> {
         return this.exec(['status', '--differ', '--merge'], reason);
     }
 
@@ -655,7 +656,7 @@ export class OpenedRepository {
     async config<T extends ConfigKey>(keys: T[]): Promise<Map<T, string>> {
         const result = await this.exec(
             ['sqlite', '--readonly'],
-            'reading configuration for github',
+            'reading configuration for github' as Reason,
             {
                 stdin_data:
                     '.mode json\n' +
diff --git a/src/preview.ts b/src/preview.ts
index 454e483..9d9b886 100644
--- a/src/preview.ts
+++ b/src/preview.ts
@@ -1,4 +1,9 @@
-import { FossilExecutable, FossilCWD, FossilArgs } from './fossilExecutable';
+import {
+    FossilExecutable,
+    FossilCWD,
+    FossilArgs,
+    Reason,
+} from './fossilExecutable';
 import * as path from 'path';
 import {
     Uri,
@@ -271,7 +276,7 @@ class FossilPreview implements IDisposable {
                     mimetype,
                     ...(where == 'Technote' ? ['--technote', 'now'] : []),
                 ],
-                '',
+                '' as Reason,
                 {
                     stdin_data: source,
                 }
@@ -303,10 +308,15 @@ class FossilPreview implements IDisposable {
                 ];
             }
 
-            const result = await this.executable.exec(this.dirname, args, '', {
-                stdin_data: this.current_content[0],
-                logErrors: false,
-            });
+            const result = await this.executable.exec(
+                this.dirname,
+                args,
+                'preview' as Reason,
+                {
+                    stdin_data: this.current_content[0],
+                    logErrors: false,
+                }
+            );
             let html: RenderedHTML;
             if (!result.exitCode) {
                 html = result.stdout as RenderedHTML;
diff --git a/src/repository.ts b/src/repository.ts
index e3c0249..e9f7cf6 100644
--- a/src/repository.ts
+++ b/src/repository.ts
@@ -73,7 +73,7 @@ import type { InteractionAPI, NewBranchOptions } from './interaction';
 import { FossilUriParams, toFossilUri } from './uri';
 
 import { localize } from './main';
-import type { ExecFailure, ExecResult } from './fossilExecutable';
+import type { ExecFailure, ExecResult, Reason } from './fossilExecutable';
 const iconsRootPath = path.join(path.dirname(__dirname), 'resources', 'icons');
 
 type AvailableIcons =
@@ -427,7 +427,7 @@ export class Repository implements IDisposable, InteractionAPI {
         );
         this._sourceControl.statusBarCommands = statusBar.commands;
 
-        this.updateModelState('opening repository');
+        this.updateModelState('opening repository' as Reason);
 
         this.disposables.push(new AutoIncomingOutgoing(this));
     }
@@ -440,7 +440,7 @@ export class Repository implements IDisposable, InteractionAPI {
     }
 
     @throttle
-    async status(reason: string): Promise<ExecResult> {
+    async status(reason: Reason): Promise<ExecResult> {
         const statusPromise = this.repository.getStatus(reason);
         await this.runWithProgress(Operation.Status, () => statusPromise);
         this.updateInputBoxPlaceholder();
@@ -467,7 +467,7 @@ export class Repository implements IDisposable, InteractionAPI {
     @throttle
     private async updateWhenIdleAndWait(): Promise<void> {
         await this.whenIdleAndFocused();
-        await this.updateModelState('idle update');
+        await this.updateModelState('idle update' as Reason);
         await delay(5000);
     }
 
@@ -1065,7 +1065,7 @@ export class Repository implements IDisposable, InteractionAPI {
      */
     @throttle
     public async updateModelState(
-        reason = 'model state is updating'
+        reason: Reason = 'model state is updating' as Reason
     ): Promise<ExecFailure | undefined> {
         const result = await this.repository.getStatus(reason);
         if (result.exitCode) {
diff --git a/src/test/suite/mergeSuite.ts b/src/test/suite/mergeSuite.ts
index cdc6f30..1c39a00 100644
--- a/src/test/suite/mergeSuite.ts
+++ b/src/test/suite/mergeSuite.ts
@@ -14,6 +14,7 @@ import * as assert from 'assert/strict';
 import * as fs from 'fs/promises';
 import { FossilBranch, OpenedRepository } from '../../openedRepository';
 import { Suite } from 'mocha';
+import { Reason } from '../../fossilExecutable';
 
 export function MergeSuite(this: Suite): void {
     test('Merge error is shown', async () => {
@@ -112,7 +113,7 @@ export function MergeSuite(this: Suite): void {
         sinon.assert.calledOnce(sqp);
         sinon.assert.calledOnce(sib);
 
-        await repository.updateModelState('test');
+        await repository.updateModelState('test' as Reason);
         assertGroups(repository, new Map(), new Map());
     }).timeout(5000);
 
diff --git a/src/test/suite/renameSuite.ts b/src/test/suite/renameSuite.ts
index f1ca3f5..7547980 100644
--- a/src/test/suite/renameSuite.ts
+++ b/src/test/suite/renameSuite.ts
@@ -14,6 +14,7 @@ import * as fs from 'fs/promises';
 import { OpenedRepository, ResourceStatus } from '../../openedRepository';
 import { delay, eventToPromise } from '../../util';
 import { Suite, before } from 'mocha';
+import { Reason } from '../../fossilExecutable';
 
 export function RenameSuite(this: Suite): void {
     before(async () => {
@@ -81,7 +82,7 @@ export function RenameSuite(this: Suite): void {
         sinon.assert.calledOnceWithExactly(
             status,
             ['status', '--differ', '--merge'],
-            'file rename event'
+            'file rename event' as Reason
         );
         sinon.assert.calledOnceWithExactly(
             sim,
diff --git a/src/test/suite/resourceActionsSuite.ts b/src/test/suite/resourceActionsSuite.ts
index 6c78ca5..95d575b 100644
--- a/src/test/suite/resourceActionsSuite.ts
+++ b/src/test/suite/resourceActionsSuite.ts
@@ -8,7 +8,7 @@ import {
     TextDocumentShowOptions,
 } from 'vscode';
 import * as sinon from 'sinon';
-import { FossilCWD } from '../../fossilExecutable';
+import { FossilCWD, Reason } from '../../fossilExecutable';
 import {
     assertGroups,
     cleanupFossil,
@@ -76,7 +76,7 @@ export function resourceActionsSuite(this: Suite): void {
         let statusStub = fakeFossilStatus(execStub, 'EXTRA a.txt\nEXTRA b.txt');
 
         const repository = getRepository();
-        await repository.updateModelState('test');
+        await repository.updateModelState('test' as Reason);
         sinon.assert.calledOnce(statusStub);
         assert.equal(repository.untrackedGroup.resourceStates.length, 2);
         assertGroups(repository, new Map(), new Map());
@@ -105,7 +105,7 @@ export function resourceActionsSuite(this: Suite): void {
         await cleanupFossil(repository);
         const execStub = getExecStub(this.ctx.sandbox);
         const statusStub = fakeFossilStatus(execStub, 'ADDED a\nADDED b');
-        await repository.updateModelState('test');
+        await repository.updateModelState('test' as Reason);
         sinon.assert.calledOnce(statusStub);
         assert.equal(repository.workingGroup.resourceStates.length, 2);
         assert.equal(repository.stagingGroup.resourceStates.length, 0);
diff --git a/src/test/suite/stateSuite.ts b/src/test/suite/stateSuite.ts
index 1b18c83..f2e4b11 100644
--- a/src/test/suite/stateSuite.ts
+++ b/src/test/suite/stateSuite.ts
@@ -11,6 +11,7 @@ import * as assert from 'assert/strict';
 import * as fs from 'fs/promises';
 import { OpenedRepository } from '../../openedRepository';
 import { Suite, before } from 'mocha';
+import { Reason } from '../../fossilExecutable';
 
 function PullAndPushSuite(this: Suite): void {
     const noRemotes = async (
@@ -432,7 +433,7 @@ export function StageSuite(this: Suite): void {
         const execStub = getExecStub(this.ctx.sandbox);
         await fakeFossilStatus(execStub, status);
         const repository = getRepository();
-        await repository.updateModelState('test');
+        await repository.updateModelState('test' as Reason);
     };
 
     test('Stage from working group', async () => {