pipeline used to build, now fails, what changed? npm install -g yarn produces error code: EExist

[oliver_browne]

Normally my first step in my pipeline (.yml) file would be:

npm install -g yarn

This has worked fine up until and including yesterday, but today produces this error: 

+ npm install -g yarn
npm ERR! code EEXIST
npm ERR! syscall symlinknpm ERR! path ../lib/node_modules/yarn/bin/yarn.js
npm ERR! dest /usr/local/bin/yarn
npm ERR! errno -17npm ERR! EEXIST: file already exists, symlink '../lib/node_modules/yarn/bin/yarn.js' -> '/usr/local/bin/yarn'
npm ERR! File exists: /usr/local/bin/yarn
npm ERR! Remove the existing file and try again, or run npm
npm ERR! with --force to overwrite files recklessly.
npm ERR! A complete log of this run can be found in:
npm ERR!     /root/.npm/_logs/2019-12-19T09_14_51_680Z-debug.log

As far as I know I haven't changed anything else - I am re-running an existing pipeline, which ran fine yesterday.  Any ideas what is happening here?  Log is below...

+ cat /root/.npm/_logs/*-debug.log
0 info it worked if it ends with ok
1 verbose cli [ '/usr/local/bin/node',1 verbose cli   '/usr/local/bin/npm',1 verbose cli   'install',
1 verbose cli   '-g',1 verbose cli   'yarn' ]
2 info using npm@6.13.4
3 info using node@v10.18.0
4 verbose npm-session fafe9701af5a68cf
5 silly install loadCurrentTree
6 silly install readGlobalPackageData
7 http fetch GET 200 https://registry.npmjs.org/yarn 125ms
8 silly pacote tag manifest for yarn@latest fetched in 148ms
9 timing stage:loadCurrentTree Completed in 175ms
10 silly install loadIdealTree
11 silly install cloneCurrentTreeToIdealTree
12 timing stage:loadIdealTree:cloneCurrentTree Completed in 0ms
13 silly install loadShrinkwrap
14 timing stage:loadIdealTree:loadShrinkwrap Completed in 3ms15 silly install loadAllDepsIntoIdealTree
16 silly resolveWithNewModule yarn@1.21.1 checking installable status
17 timing stage:loadIdealTree:loadAllDepsIntoIdealTree Completed in 6ms
18 timing stage:loadIdealTree Completed in 14ms
19 silly currentTree lib20 silly idealTree lib
20 silly idealTree `-- yarn@1.21.1
21 silly install generateActionsToTake
22 timing stage:generateActionsToTake Completed in 3ms
23 silly diffTrees action count 1
24 silly diffTrees add yarn@1.21.1
25 silly decomposeActions action count 8
26 silly decomposeActions fetch yarn@1.21.1
27 silly decomposeActions extract yarn@1.21.1
28 silly decomposeActions preinstall yarn@1.21.1
29 silly decomposeActions build yarn@1.21.1
30 silly decomposeActions install yarn@1.21.1
31 silly decomposeActions postinstall yarn@1.21.1
32 silly decomposeActions finalize yarn@1.21.1
33 silly decomposeActions refresh-package-json yarn@1.21.1
34 silly install executeActions
35 silly doSerial global-install 8
36 verbose correctMkdir /root/.npm/_locks correctMkdir not in flight; initializing
37 verbose lock using /root/.npm/_locks/staging-3a08f0df5026584d.lock for /usr/local/lib/node_modules/.staging
38 silly doParallel extract 1
39 silly extract yarn@1.21.1
40 silly tarball trying yarn@latest by hash: sha512-dQgmJv676X/NQczpbiDtc2hsE/pppGDJAzwlRiADMTvFzYbdxPj2WO4PcNyriSt2c4jsCMpt8UFRKHUozt21GQ==
41 silly tarball no local data for yarn@latest. Extracting by manifest.
42 http fetch GET 200 https://registry.npmjs.org/yarn/-/yarn-1.21.1.tgz 234ms
43 silly extract yarn@latest extracted to /usr/local/lib/node_modules/.staging/yarn-53412bb0 (249ms)
44 timing action:extract Completed in 252ms
45 silly doReverseSerial unbuild 8
46 silly doSerial remove 8
47 silly doSerial move 8
48 silly doSerial finalize 8
49 silly finalize /usr/local/lib/node_modules/yarn
50 timing action:finalize Completed in 8ms
51 silly doParallel refresh-package-json 1
52 silly refresh-package-json /usr/local/lib/node_modules/yarn
53 timing action:refresh-package-json Completed in 33ms
54 silly doParallel preinstall 1
55 silly preinstall yarn@1.21.1
56 info lifecycle yarn@1.21.1~preinstall: yarn@1.21.1
57 timing action:preinstall Completed in 2ms
58 silly doSerial build 8
59 silly build yarn@1.21.1
60 info linkStuff yarn@1.21.1
61 silly linkStuff yarn@1.21.1 has /usr/local/lib/node_modules as its parent node_modules
62 silly linkStuff yarn@1.21.1 is part of a global install
63 silly linkStuff yarn@1.21.1 is installed into a global node_modules
64 silly linkStuff yarn@1.21.1 is installed into the top-level global node_modules65 verbose linkBins [ { yarn: 'bin/yarn.js', yarnpkg: 'bin/yarn.js' },
65 verbose linkBins   '/usr/local/bin',65 verbose linkBins   true ]66 verbose gently link refusing to delete existing link { link: '/usr/local/bin/yarn',
66 verbose gently link   currentTarget: '/opt/yarn-v1.21.1/bin/yarnpkg',
66 verbose gently link   newTarget: '/usr/local/lib/node_modules/yarn/bin/yarn.js',
66 verbose gently link   gently: '/usr/local/lib/node_modules/yarn' }67 verbose gently link refusing to delete existing link { link: '/usr/local/bin/yarnpkg',
67 verbose gently link   currentTarget: '/opt/yarn-v1.21.1/bin/yarnpkg',67 verbose gently link   newTarget: '/usr/local/lib/node_modules/yarn/bin/yarn.js',
67 verbose gently link   gently: '/usr/local/lib/node_modules/yarn' }
68 timing action:build Completed in 7ms
69 verbose unlock done using /root/.npm/_locks/staging-3a08f0df5026584d.lock for /usr/local/lib/node_modules/.staging
70 timing stage:rollbackFailedOptional Completed in 11ms
71 timing stage:runTopLevelLifecycles Completed in 518ms
72 verbose stack Error: EEXIST: file already exists, symlink '../lib/node_modules/yarn/bin/yarn.js' -> '/usr/local/bin/yarn'
73 verbose cwd /opt/atlassian/pipelines/agent/build
74 verbose Linux 4.19.78-coreos
75 verbose argv "/usr/local/bin/node" "/usr/local/bin/npm" "install" "-g" "yarn"
76 verbose node v10.18.0
77 verbose npm  v6.13.4
78 error code EEXIST
79 error syscall symlink
80 error path ../lib/node_modules/yarn/bin/yarn.js
81 error dest /usr/local/bin/yarn
82 error errno -1783 error EEXIST: file already exists, symlink '../lib/node_modules/yarn/bin/yarn.js' -> '/usr/local/bin/yarn'
84 error File exists: /usr/local/bin/yarn
85 error Remove the existing file and try again, or run npm
86 error with --force to overwrite files recklessly.
87 verbose exit [ -17, true ] 

[oliver_browne · Accepted solution]

Turns out switching:

npm install -g yarn

to

 npm install yarn

was sufficient to resolve this problem.

I have not found out why it worked previously up until yesterday but now no longer works.