cd ~/MagicMirror
npm install
npm start

Upgrade started - Wed Jul 8 14:29:34 CDT 2020
system is Linux raspberrypi 4.19.118-v7+ #1311 SMP Mon Apr 27 14:21:24 BST 2020 armv7l GNU/Linux
the os is Distributor ID: Raspbian Description: Raspbian GNU/Linux 10 (buster) Release: 10 Codename: buster
user requested to force apply changes
doing test run = false

saving custom.css
remote name = origin
upgrading from version 2.12.0 to 2.12.0
fetching latest revisions
git fetch rc=0
current branch = master
On branch master
Your branch is up to date with ‘origin/master’.

Changes not staged for commit:
(use “git add/rm …” to update what will be committed)
(use “git checkout – …” to discard changes in working directory)

deleted:    package-lock.json

Untracked files:
(use “git add …” to include in what will be committed)

css/save_custom.css
run-start.sh

no changes added to commit (use “git add” and/or “git commit -a”)
no files different from github version
test merge result rc=‘’ , if empty, no conflicts
executing merge, apply specified
merge result rc= 0
Already up to date.
processor architecture is armv7l
updating MagicMirror runtime, please wait
npm WARN deprecated left-pad@1.3.0: use String.prototype.padStart()
npm WARN deprecated webdriverio@4.14.4: outdated version, please use @next
npm WARN deprecated mkdirp@0.5.1: Legacy versions of mkdirp are no longer supported. Please update to mkdirp 1.x. (Note that the API surface has changed to use Promises in 1.x.)
npm WARN registry Unexpected warning for https://registry.npmjs.org/: Miscellaneous Warning EAI_AGAIN: request to https://registry.npmjs.org/css-value failed, reason: getaddrinfo EAI_AGAIN registry.npmjs.org registry.npmjs.org:443
npm WARN registry Using stale data from https://registry.npmjs.org/ due to a request error during revalidation.
npm WARN deprecated core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
npm WARN deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
npm WARN deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated

magicmirror@2.12.0 install /home/pi/MagicMirror
echo "Installing vendor files …
" && cd vendor && npm install --loglevel=error

Installing vendor files …

Upgrade started - Wed Jul 8 15:44:11 CDT 2020
system is Linux raspberrypi 4.19.118-v7+ #1311 SMP Mon Apr 27 14:21:24 BST 2020 armv7l GNU/Linux
the os is Distributor ID: Raspbian Description: Raspbian GNU/Linux 10 (buster) Release: 10 Codename: buster
user requested to force apply changes
doing test run = false

saving custom.css
remote name = origin
upgrading from version 2.12.0 to 2.12.0
fetching latest revisions
git fetch rc=0
current branch = master
On branch master
Your branch is up to date with ‘origin/master’.

Changes not staged for commit:
(use “git add/rm …” to update what will be committed)
(use “git checkout – …” to discard changes in working directory)

deleted:    package-lock.json

Untracked files:
(use “git add …” to include in what will be committed)

css/save_custom.css
run-start.sh

no changes added to commit (use “git add” and/or “git commit -a”)
no files different from github version
test merge result rc=‘’ , if empty, no conflicts
executing merge, apply specified
merge result rc= 0
Already up to date.
processor architecture is armv7l
updating MagicMirror runtime, please wait
npm WARN deprecated left-pad@1.3.0: use String.prototype.padStart()
npm WARN deprecated webdriverio@4.14.4: outdated version, please use @next
npm WARN deprecated mkdirp@0.5.1: Legacy versions of mkdirp are no longer supported. Please update to mkdirp 1.x. (Note that the API surface has changed to use Promises in 1.x.)
npm WARN deprecated core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
npm WARN deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
npm WARN deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated

magicmirror@2.12.0 install /home/pi/MagicMirror
echo "Installing vendor files …
" && cd vendor && npm install --loglevel=error

Installing vendor files …

added 82 packages from 57 contributors and audited 150 packages in 12.974s
found 8 vulnerabilities (7 low, 1 high)
run npm audit fix to fix them, or npm audit for details

magicmirror@2.12.0 postinstall /home/pi/MagicMirror
npm run install-fonts && echo "MagicMirror installation finished successfully!
"

magicmirror@2.12.0 install-fonts /home/pi/MagicMirror
echo "Installing fonts …
" && cd fonts && npm install --loglevel=error

Installing fonts …

added 1 package from 1 contributor and audited 1 package in 1.285s
found 0 vulnerabilities

MagicMirror installation finished successfully!

npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@~2.1.1 (node_modules/chokidar/node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.1.3: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“arm”})

audited 1042 packages in 69.581s

11 packages are looking for funding
run npm fund for details

found 3 low severity vulnerabilities
run npm audit fix to fix them, or npm audit for details
npm install completed - Wed Jul 8 15:45:29 CDT 2020 on base
downloading dumpactivemodules script
no modules found needing npm refresh
restoring custom.css
removing git alias
Upgrade ended - Wed Jul 8 15:45:30 CDT 2020

Upgrade started - Wed Jul 8 14:21:46 CDT 2020
system is Linux raspberrypi 4.19.118-v7+ #1311 SMP Mon Apr 27 14:21:24 BST 2020 armv7l GNU/Linux
the os is Distributor ID: Raspbian Description: Raspbian GNU/Linux 10 (buster) Release: 10 Codename: buster
doing test run = true, NO updates will be applied!

saving custom.css
remote name = origin
upgrading from version 2.12.0 to 2.12.0
fetching latest revisions
git fetch rc=0
current branch = master
On branch master
Your branch is up to date with ‘origin/master’.

Changes not staged for commit:
(use “git add/rm …” to update what will be committed)
(use “git checkout – …” to discard changes in working directory)

deleted:    package-lock.json

Untracked files:
(use “git add …” to include in what will be committed)

css/save_custom.css
run-start.sh

no changes added to commit (use “git add” and/or “git commit -a”)
no files different from github version
test merge result rc=‘’ , if empty, no conflicts
skipping merge, only test run
downloading dumpactivemodules script
no modules found needing npm refresh
restoring custom.css
removing git alias
Upgrade ended - Wed Jul 8 14:21:51 CDT 2020

Upgrade started - Wed Jul 8 14:22:11 CDT 2020
system is Linux raspberrypi 4.19.118-v7+ #1311 SMP Mon Apr 27 14:21:24 BST 2020 armv7l GNU/Linux
the os is Distributor ID: Raspbian Description: Raspbian GNU/Linux 10 (buster) Release: 10 Codename: buster
user requested to apply changes
doing test run = false

saving custom.css
remote name = origin
local version 2.12.0 already same as master 2.12.0
restoring custom.css
removing git alias
Upgrade ended - Wed Jul 8 14:22:12 CDT 2020

can u show me the ~/MagicMirror/installers/upgrade.log

I am on Pi 3 ( I am a novice to MM. where do I run isb_release -a for the info you requested? on the terminal?)

I used your script to upgrade.

what pi are u on and what is level?
run
lsb_release -a
for that is info