wrap setting err.message with a try/catch - #2996

~/Repositories/_FORKED/pug:$ npx yarn test -u
npx: installed 1 in 1.098s
yarn run v1.17.3
$ lerna run pretest
lerna notice cli v3.10.8
lerna info versioning independent
lerna info Executing command in 1 package: "yarn run pretest"
lerna ERR! yarn run pretest exited 1 in 'pug-runtime'
lerna ERR! yarn run pretest stdout:
$ npm run prepublish

> pug-runtime@2.0.5 prepublish /Users/Chris/Repositories/_FORKED/pug/packages/pug-runtime
> node prepublish

info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

lerna ERR! yarn run pretest stderr:
npm WARN lifecycle The node binary used for scripts is /var/folders/1c/lvpbw7yx2bngjzt7vkwt023r0000gn/T/yarn--1563760108313-0.08699649989854286/node but npm is using /usr/local/bin/node itself. Use the `--scripts-prepend-node-path` option to include the path for the node binary npm was executed with.
undefined:2001
            S.token = S.input();
                        ^

TypeError: S.input is not a function
    at next (eval at <anonymous> (/Users/Chris/Repositories/_FORKED/pug/node_modules/uglify-js/tools/node.js:20:1), <anonymous>:2001:25)
    at Object.parse (eval at <anonymous> (/Users/Chris/Repositories/_FORKED/pug/node_modules/uglify-js/tools/node.js:20:1), <anonymous>:1985:15)
    at /Users/Chris/Repositories/_FORKED/pug/packages/pug-runtime/prepublish.js:32:22
    at Array.forEach (<anonymous>)
    at Object.<anonymous> (/Users/Chris/Repositories/_FORKED/pug/packages/pug-runtime/prepublish.js:18:10)
    at Module._compile (internal/modules/cjs/loader.js:701:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:712:10)
    at Module.load (internal/modules/cjs/loader.js:600:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:539:12)
    at Function.Module._load (internal/modules/cjs/loader.js:531:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! pug-runtime@2.0.5 prepublish: `node prepublish`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the pug-runtime@2.0.5 prepublish script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm WARN Local package.json exists, but node_modules missing, did you mean to install?

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/Chris/.npm/_logs/2019-07-22T01_48_28_732Z-debug.log
error Command failed with exit code 1.

lerna ERR! yarn run pretest exited 1 in 'pug-runtime'
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.