Reactをfirebaseでデプロイできない

ついに作ったReactを、いったんデプロイ、というものをしようとしています。
こちらを参考にfirebaseをやってみて進んだのですが、npm run buildの段階でエラーが出ました

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! sample@0.1.0 build: `react-scripts build`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the sample@0.1.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/stepfstep/.npm/_logs/2020-04-08T16_58_51_868Z-debug.log

また、エラーログにはこのように表示されています

0 info it worked if it ends with ok
1 verbose cli [
1 verbose cli   '/Users/stepfstep/.nodebrew/node/v12.16.1/bin/node',
1 verbose cli   '/Users/stepfstep/.nodebrew/current/bin/npm',
1 verbose cli   'run',
1 verbose cli   'build'
1 verbose cli ]
2 info using npm@6.13.4
3 info using node@v12.16.1
4 verbose run-script [ 'prebuild', 'build', 'postbuild' ]
5 info lifecycle sample@0.1.0~prebuild: sample@0.1.0
6 info lifecycle sample@0.1.0~build: sample@0.1.0
7 verbose lifecycle sample@0.1.0~build: unsafe-perm in lifecycle true
8 verbose lifecycle sample@0.1.0~build: PATH: /Users/stepfstep/.nodebrew/node/v12.16.1/lib/node_modules/npm/node_modules/npm-lifecycle/node-gyp-bin:/Users/stepfstep/自作application/Big5.5_front/node_modules/.bin:/Users/stepfstep/.nodebrew/current/bin:/Users/stepfstep/.rbenv/shims:/opt/anaconda3/bin:/opt/anaconda3/condabin:/anaconda3/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin
9 verbose lifecycle sample@0.1.0~build: CWD: /Users/stepfstep/自作application/Big5.5_front
10 silly lifecycle sample@0.1.0~build: Args: [ '-c', 'react-scripts build' ]
11 silly lifecycle sample@0.1.0~build: Returned: code: 1  signal: null
12 info lifecycle sample@0.1.0~build: Failed to exec build script
13 verbose stack Error: sample@0.1.0 build: `react-scripts build`
13 verbose stack Exit status 1
13 verbose stack     at EventEmitter.<anonymous> (/Users/stepfstep/.nodebrew/node/v12.16.1/lib/node_modules/npm/node_modules/npm-lifecycle/index.js:332:16)
13 verbose stack     at EventEmitter.emit (events.js:311:20)
13 verbose stack     at ChildProcess.<anonymous> (/Users/stepfstep/.nodebrew/node/v12.16.1/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:55:14)
13 verbose stack     at ChildProcess.emit (events.js:311:20)
13 verbose stack     at maybeClose (internal/child_process.js:1021:16)
13 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:286:5)
14 verbose pkgid sample@0.1.0
15 verbose cwd /Users/stepfstep/自作application/Big5.5_front
16 verbose Darwin 19.3.0
17 verbose argv "/Users/stepfstep/.nodebrew/node/v12.16.1/bin/node" "/Users/stepfstep/.nodebrew/current/bin/npm" "run" "build"
18 verbose node v12.16.1
19 verbose npm  v6.13.4
20 error code ELIFECYCLE
21 error errno 1
22 error sample@0.1.0 build: `react-scripts build`
22 error Exit status 1
23 error Failed at the sample@0.1.0 build script.
23 error This is probably not a problem with npm. There is likely additional logging output above.
24 verbose exit [ 1, true ]

見様見真似なので、どこかで間違えていると思うのですが、どこで間違えているかの見当がつきません
。

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