gulp minify doesn't work in canvas 7

[00:19:43] Using gulpfile ~/workspace/privat/Canvas 7 Files/gulpfile.js
[00:19:43] Starting 'minify'...
[00:19:54] The following tasks did not complete: minify
[00:19:54] Did you forget to signal async completion?

seems like gulp 4 needs async completion.
please update gulpfile.js file

scsscompile doesnt work either

[00:32:33] Error in plugin "gulp-sass"
Message:
sass/_portfolio.scss
Error: Undefined operation "--cnvs-portfolio-desc-title-size * 0.8".
╷
326 │ font-size: calc(var(--#{$cnvs-prefix}portfolio-desc-title-size * 0.8) / 3);
│ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
╵
sass/_portfolio.scss 326:24 @import
style.scss 33:9 root stylesheet
Details:
formatted: Error: Undefined operation "--cnvs-portfolio-desc-title-size * 0.8".
╷
326 │ font-size: calc(var(--#{$cnvs-prefix}portfolio-desc-title-size * 0.8) / 3);
│ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
╵
sass/_portfolio.scss 326:24 @import
style.scss 33:9 root stylesheet
line: 326
column: 24
file: /Users/user/workspace/privat/Canvas 7 Files/sass/_portfolio.scss
status: 1
messageFormatted: sass/_portfolio.scss
Error: Undefined operation "--cnvs-portfolio-desc-title-size * 0.8".
╷
326 │ font-size: calc(var(--#{$cnvs-prefix}portfolio-desc-title-size * 0.8) / 3);
│ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
╵
sass/_portfolio.scss 326:24 @import
style.scss 33:9 root stylesheet
messageOriginal: Undefined operation "--cnvs-portfolio-desc-title-size * 0.8".
╷
326 │ font-size: calc(var(--#{$cnvs-prefix}portfolio-desc-title-size * 0.8) / 3);
│ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
╵
sass/_portfolio.scss 326:24 @import
style.scss 33:9 root stylesheet
relativePath: sass/_portfolio.scss
domainEmitter: [object Object]
domainThrown: false

Process finished with exit code 1