libjansi.jnilib cannot be opened because the developer cannot be verified – macOS 10.15

If you can see this error: “libjansi.jnilib” cannot be opened because the developer cannot be verified – while working on macOS 10.15 (screen shoot looks like this) it means you probably have issues with libjansi coming from Apache Maven. Make sure to upgrade to version apache-maven-3.6.2. ———— Update ———— In fact, you can do better […]


macOS 10.15 – directory size in CLI

There is this interesting article about using NCurses Disk Usage in Arch Linux – you can find here: Cleaning root partition on Linux. I definitely prefer to stick to macOS, so I have decided to get it running from iTerm2. It’s really simple. All you have to do is to (as with other samples you […]


macOS Catalina and VirtualBox issues

I had this strange issue with VirtualBox. There was this crash solution that worked for me follows source: https://forums.virtualbox.org/viewtopic.php?f=8&t=95041


macOS Mojave – make sure your system is safe
updated for ClamAV release 0.101.4

If you want to make sure that your macOS High Sierra is clean (when it comes to malicious software) you can use free tool (free as in beer and free as in speech – at the same time) called ClamAV. You can get it various ways. You can download it’s commercial version from AppStore – […]


_JAVA_OPTIONS will not always work for your Java code

It’s good to know, that _JAVA_OPTIONS will not always work in your Java code. Especially, when you elevate privileges using sudo. Let’s say we have this simple code and we run it following way As you can see, in case of second execution _JAVA_OPTIONS were not picked up. The reason for not picking it up […]


The submit token is NOT YOUR LOGIN PASSWORD.

If you are trying to submit your solution using sbt, like this. you might find this one a solution for you. Start sbt, and run submit from there.


sign_and_send_pubkey: no mutual signature supported – macOS 10.14

Just add this one inside ~/.ssh/config.


And Now for Something Completely Different – Zbudzone furie

The dusk was repeating them in a persistent whisper all around us, in a whisper that seemed to swell menacingly like the first whisper of a rising wind. ‘The horror! The horror!’


And Now for Something Completely Different – Upadłe anioły

Jedyne co mogę powiedzieć na temat tej książki, to: a = g⋅sinα


Kindle Paperwhite and hard space issue

Recently I have encountered quite frustrating issue with Kindle Paperwhite (3rd) and hard spaces inside Mobi document. At the same time (while buying the book) I have download three, different, formats: epub, Mobi and RTF. All of these have hard spaces all over the place in document. However, there is a slight difference in the […]


Samsung and scanning to PDF in macOS Mojave

… is broken. There is no way to use default Image Capture application with Samsung SCX-4500W printer. However, there is hope :) You can download Samsung Easy Document Creator from here: link. Please note that Samsung line of printers was acquired by HP – this is why you have to download application from HP’s pages. […]


How to get JAR location from JNI


And Now for Something Completely Different – Wojtek Justyna TreeOh!

Radio RAM nie zawodzi ;) Tym razem, dzięki nim, dowiedziałem się o zespole Wojtek Justyna TreeOh!. Grają niesamowicie sympatyczny, spokojny, nieprzekombinowany Jazz, którego bardzo miło się słucha – szczególnie wtedy, gdy za oknem robi się ciemno. Nienatarczywy towarzysz wieczornej lektury książek, ale jako tło dla domówki też sie nada. A tutaj link do ich strony […]


And Now for Something Completely Different – Altered Carbon

Zdecydowanie lepsza od interpretacji Netflixa


And Now for Something Completely Different – Company of One

Company of One is … everything


eternity – defined using macOS keyboard settings

To learn what eternity means, change your keyboard setting from this to this


Running JAR file from R using rJava (without spawning new process)

Let’s say we have this, very simple, structure of the project where StringTest.java is a very simple Java class while Manifest.txt contains We can easily create JAR (“executable”) from these files using jar application Now, let’s try to run this code inside R. It’s quite straightforward.


R, Java 11 and making sure you can load rJava

As usual, there are some issues with new Java releases (11 and 12) and R. If you want to run rJava package inside R you have to do few things. First, make sure you are using Java 11 as default inside terminal session. Inside ~/.profile add this line Once it’s done, you have to make […]


macOS boots to black screen of emptiness

1. disable Night Shift It looks like Mojave 10.14.5 has some issues with booting when display colours are adapted to night mode using Night Shift. After starting up my macOS based machine in the evening (when Night Shift kicks in with all the fancy colour settings) I have noticed that machine boots into black screen. […]


macOS Mojave and accessing TimeMachine’s
data from command line (iTerm2)

Whenever I restore (setup) new Mac, I do it manually. I simply install clean system, and transfer what I really need from TimeMachine’s backup – typically using CLI. In Mojave it’s a no-no. If you use iTerm2, you will face following issue while accessing data inside TimeMachine’s storage. What you have to do, is adding […]