Add more logging in case hashing fails (microsoft#6640)

Author: rchiodo

package-lock.json

@@ -14,7 +14,7 @@ import {
 } from 'vscode';
 
 import { IDebugService, IDocumentManager } from '../../common/application/types';
-import { traceError } from '../../common/logger';
+import { traceError, traceInfo } from '../../common/logger';
 import { IConfigurationService } from '../../common/types';
 import { noop } from '../../common/utils/misc';
 import { CellMatcher } from '../cellMatcher';
@@ -238,6 +238,8 @@ export class CellHashProvider implements ICellHashProvider, IInteractiveWindowLi
  id: cell.id
  };
 
+ traceInfo(`Adding hash for ${expectedCount} = ${hash.hash} with ${stripped.length} lines`);
+
  let list = this.hashes.get(cell.file);
  if (!list) {
  list = [];