about.static.pug

Having the following error when running with docker:

Error compiling about.static.pug: Error: Expected source code to be a string but got "object" at new Lexer (/coco/node_modules/pug/node_modules/pug-lexer/index.js:26:11) at lex (/coco/node_modules/pug/node_modules/pug-lexer/index.js:11:15) at Object.lex (/coco/node_modules/pug/lib/index.js:100:27) at Function.loadString [as string] (/coco/node_modules/pug/node_modules/pug-load/index.js:44:24) at /coco/node_modules/pug/node_modules/pug-load/index.js:31:27 at walkAST (/coco/node_modules/pug/node_modules/pug-walk/index.js:23:18) at /coco/node_modules/pug/node_modules/pug-walk/index.js:104:20 at Array.reduce (<anonymous>:null:null) at walkAndMergeNodes (/coco/node_modules/pug/node_modules/pug-walk/index.js:103:18) at walkAST (/coco/node_modules/pug/node_modules/pug-walk/index.js:37:19) at load (/coco/node_modules/pug/node_modules/pug-load/index.js:13:10) at Function.loadString [as string] (/coco/node_modules/pug/node_modules/pug-load/index.js:46:10) at compileBody (/coco/node_modules/pug/lib/index.js:86:18) at Object.exports.compileClientWithDependenciesTracked (/coco/node_modules/pug/lib/index.js:290:16) at compile (/coco/compile-static-templates.js:53:17) at /coco/compile-static-templates.js:186:9 at Hook.eval [as callAsync] (<anonymous>:29:1) at Hook.CALL_ASYNC_DELEGATE [as _callAsync] (/coco/node_modules/tapable/lib/Hook.js:18:14) at Compiler.emitAssets (/coco/node_modules/webpack/lib/Compiler.js:996:19) at /coco/node_modules/webpack/lib/Compiler.js:508:10 at processTicksAndRejections (internal/process/task_queues.js:77:11)