Julia hanging (/pausing indefinitely) on package build of MbedTLS and others


I am having a very strange issue on Windows 10. Whenever the Julia package manager needs to build the MbedTLS package it hangs (or pauses indefinitely) at

INFO: Building MbedTLS

Opening task manager shows now CPU usage or change in memory consumption by Julia. It seems to just sit in this state indefinitely without indicating any error or issue. The only way I was able to get around this issue was by

  1. Closing the Julia terminal
  2. Opening a new Julia terminal
  3. Pkg.rm(“MbedTLS”)
  4. Removing the MbedTLS folder from the .julia/v0.6/cache folder
  5. Pkg.add(“MbedTLS”)

The package manager then successfully completes the build/add process.

I have had this issue arise in the past with other packages (ZMQ I think? and possibly also PyCall?). I think in those cases I completely nuked my .julia directory before I realized that I could just clear .cache.

Does anyone know why this might be happening?

Is there any way that I can get more verbose output from Pkg.build() in order to figure out what’s going on?


As a follow up to the above, I just updated to Julia 0.6.3 and consequently had to rebuild IJulia. On my first try I specified


and had Julia hang in the same manner as described above with MbedTLS at

INFO: Building IJulia

After following the same procedure of removing the packages and deleting .cache/IJulia and .cache/MbedTLS and correcting my path to Jupyter to be:


I was then able to complete the build process.

It seems very strange that these operations would be failing silently like this. Please let me know if anyone has a clue as to what’s going on.