Error after downgrade 4.6.0 to 3.12.0

#1

Hi all!

I downgraded my ionic version to 3.12.0 from the last (4.6.0) which I have installed for a mistake.
Now, when I try to start a new project, I obtain this error:

PS C:\Users\anton\Desktop> ionic start BackupApp blank
√ Creating directory .\BackupApp - done!
[INFO] Fetching app base (https://github.com/ionic-team/ionic2-app-base/archive/master.tar.gz)
√ Downloading - done!
[INFO] Fetching starter template blank (https://github.com/ionic-team/ionic2-starter-blank/archive/master.tar.gz)
√ Downloading - done!
√ Updating package.json with app details - done!
√ Creating configuration file ionic.config.json - done!
[INFO] Installing dependencies may take several minutes!
> npm install
× Running command - failed!
[ERROR] An error occurred while running npm install (exit code 1):


        npm WARN deprecated browserslist@2.11.3: Browserslist 2 could fail on reading Browserslist >3.0 config used in
        other tools.

        > node-sass@4.5.3 install C:\Users\anton\Desktop\BackupApp\node_modules\node-sass
        > node scripts/install.js

        Downloading binary from https://github.com/sass/node-sass/releases/download/v4.5.3/win32-x64-64_binding.node
        Cannot download "https://github.com/sass/node-sass/releases/download/v4.5.3/win32-x64-64_binding.node":

        HTTP error 404 Not Found

        Hint: If github.com is not accessible in your location
               try setting a proxy via HTTP_PROXY, e.g.

               export HTTP_PROXY=http://example.com:1234

        or configure npm proxy via

               npm config set proxy http://example.com:8080

        > uglifyjs-webpack-plugin@0.4.6 postinstall
        C:\Users\anton\Desktop\BackupApp\node_modules\uglifyjs-webpack-plugin
        > node lib/post_install.js


        > node-sass@4.5.3 postinstall C:\Users\anton\Desktop\BackupApp\node_modules\node-sass
        > node scripts/build.js

        Building: C:\Program Files\nodejs\node.exe
        C:\Users\anton\Desktop\BackupApp\node_modules\node-gyp\bin\node-gyp.js rebuild --verbose --libsass_ext=
        --libsass_cflags= --libsass_ldflags= --libsass_library=
        gyp info it worked if it ends with ok
        gyp verb cli [ 'C:\\Program Files\\nodejs\\node.exe',
        gyp verb cli   'C:\\Users\\anton\\Desktop\\BackupApp\\node_modules\\node-gyp\\bin\\node-gyp.js',
        gyp verb cli   'rebuild',
        gyp verb cli   '--verbose',
        gyp verb cli   '--libsass_ext=',
        gyp verb cli   '--libsass_cflags=',
        gyp verb cli   '--libsass_ldflags=',
        gyp verb cli   '--libsass_library=' ]
        gyp info using node-gyp@3.8.0
        gyp info using node@10.14.1 | win32 | x64
        gyp verb command rebuild []
        gyp verb command clean []
        gyp verb clean removing "build" directory
        gyp verb command configure []
        gyp verb check python checking for Python executable "python2" in the PATH
        gyp verb `which` failed Error: not found: python2
        gyp verb `which` failed     at getNotFoundError
        (C:\Users\anton\Desktop\BackupApp\node_modules\which\which.js:13:12)
        gyp verb `which` failed     at F (C:\Users\anton\Desktop\BackupApp\node_modules\which\which.js:68:19)
        gyp verb `which` failed     at E (C:\Users\anton\Desktop\BackupApp\node_modules\which\which.js:80:29)
        gyp verb `which` failed     at C:\Users\anton\Desktop\BackupApp\node_modules\which\which.js:89:16
        gyp verb `which` failed     at C:\Users\anton\Desktop\BackupApp\node_modules\isexe\index.js:42:5
        gyp verb `which` failed     at C:\Users\anton\Desktop\BackupApp\node_modules\isexe\windows.js:36:5
        gyp verb `which` failed     at FSReqWrap.oncomplete (fs.js:154:21)
        gyp verb `which` failed  python2 { Error: not found: python2
        gyp verb `which` failed     at getNotFoundError
        (C:\Users\anton\Desktop\BackupApp\node_modules\which\which.js:13:12)
        gyp verb `which` failed     at F (C:\Users\anton\Desktop\BackupApp\node_modules\which\which.js:68:19)
        gyp verb `which` failed     at E (C:\Users\anton\Desktop\BackupApp\node_modules\which\which.js:80:29)
        gyp verb `which` failed     at C:\Users\anton\Desktop\BackupApp\node_modules\which\which.js:89:16
        gyp verb `which` failed     at C:\Users\anton\Desktop\BackupApp\node_modules\isexe\index.js:42:5
        gyp verb `which` failed     at C:\Users\anton\Desktop\BackupApp\node_modules\isexe\windows.js:36:5
        gyp verb `which` failed     at FSReqWrap.oncomplete (fs.js:154:21)
        gyp verb `which` failed   stack:
        gyp verb `which` failed    'Error: not found: python2\n    at getNotFoundError
        (C:\\Users\\anton\\Desktop\\BackupApp\\node_modules\\which\\which.js:13:12)\n    at F
        (C:\\Users\\anton\\Desktop\\BackupApp\\node_modules\\which\\which.js:68:19)\n    at E
        (C:\\Users\\anton\\Desktop\\BackupApp\\node_modules\\which\\which.js:80:29)\n    at
        C:\\Users\\anton\\Desktop\\BackupApp\\node_modules\\which\\which.js:89:16\n    at
        C:\\Users\\anton\\Desktop\\BackupApp\\node_modules\\isexe\\index.js:42:5\n    at
        C:\\Users\\anton\\Desktop\\BackupApp\\node_modules\\isexe\\windows.js:36:5\n    at FSReqWrap.oncomplete
        (fs.js:154:21)',
        gyp verb `which` failed   code: 'ENOENT' }
        gyp verb check python checking for Python executable "python" in the PATH
        gyp verb `which` succeeded python C:\ProgramData\Anaconda3\python.EXE
        gyp ERR! configure error
        gyp ERR! stack Error: Command failed: C:\ProgramData\Anaconda3\python.EXE -c import sys; print "%s.%s.%s" %
        sys.version_info[:3];
        gyp ERR! stack   File "<string>", line 1
        gyp ERR! stack     import sys; print "%s.%s.%s" % sys.version_info[:3];
        gyp ERR! stack                                ^
        gyp ERR! stack SyntaxError: invalid syntax
        gyp ERR! stack
        gyp ERR! stack     at ChildProcess.exithandler (child_process.js:289:12)
        gyp ERR! stack     at ChildProcess.emit (events.js:182:13)
        gyp ERR! stack     at maybeClose (internal/child_process.js:962:16)
        gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:251:5)
        gyp ERR! System Windows_NT 10.0.17134
        gyp ERR! command "C:\\Program Files\\nodejs\\node.exe"
        "C:\\Users\\anton\\Desktop\\BackupApp\\node_modules\\node-gyp\\bin\\node-gyp.js" "rebuild" "--verbose"
        "--libsass_ext=" "--libsass_cflags=" "--libsass_ldflags=" "--libsass_library="
        gyp ERR! cwd C:\Users\anton\Desktop\BackupApp\node_modules\node-sass
        gyp ERR! node -v v10.14.1
        gyp ERR! node-gyp -v v3.8.0
        gyp ERR! not ok
        Build failed with error code: 1
        npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules\fsevents):
        npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted
        {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})

        npm ERR! code ELIFECYCLE
        npm ERR! errno 1
        npm ERR! node-sass@4.5.3 postinstall: `node scripts/build.js`
        npm ERR! Exit status 1
        npm ERR!
        npm ERR! Failed at the node-sass@4.5.3 postinstall 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!     C:\Users\anton\AppData\Roaming\npm-cache\_logs\2018-12-24T15_10_04_936Z-debug.log

Here my ionic info:

cli packages: (C:\Users\anton\AppData\Roaming\npm\node_modules)

    @ionic/cli-utils  : 1.12.0
    ionic (Ionic CLI) : 3.12.0

System:

    Node : v10.14.1
    npm  : 6.4.1
    OS   : Windows 10

Misc:

    backend : pro

Could someone help me?
Thank you!

#2

this is so sad that most of the ionic issues are left without answers in every website! some of them are for 2017!!!