# Compiling a project specific sysimage
**URL:** https://discourse.julialang.org/t/compiling-a-project-specific-sysimage/47902
**Category:** Tooling
**Tags:** precompilation, package-compiler, sysimage
**Created:** [October 6, 2020, 11:20pm UTC](https://discourse.julialang.org/t/compiling-a-project-specific-sysimage/47902 "2020-10-06T23:20:53Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@martenlienen](https://discourse.julialang.org/u/martenlienen)
#### Post date: [October 6, 2020, 11:20pm UTC](https://discourse.julialang.org/t/compiling-a-project-specific-sysimage/47902/1 "2020-10-06T23:20:53Z")
I am getting started with Julia and having a good time. One thing I dislike quite a bit though is the slow startup time of a REPL when you import some costly packages in the beginning. As far as I can tell the best way to work around this is to compile a custom sysimage with PackageCompiler.jl which I did. It works great for some packages like Plots.jl but others refuse to be precompiled and if you try, the sysimage segfaults on load. Instead of fixing the root cause, I decided to write a script that still allows me to precompile as many things as possible anyway.
[https://gist.github.com/cqql/d4ab84617a8e532dc0cedcd5469fb715](https://gist.github.com/cqql/d4ab84617a8e532dc0cedcd5469fb715)
It lists a project’s dependencies and then compiles them one by one incrementally into a sysimage, checking at each step if the image still loads.
Is there a better/established way to go about this that I missed? As I am still learning the language, is there code in the script that could be written more idiomatically?
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### Author:  [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)
#### Post date: [October 6, 2020, 11:55pm UTC](https://discourse.julialang.org/t/compiling-a-project-specific-sysimage/47902/2 "2020-10-06T23:55:51Z")
Note that all parts of this are getting better in 1.6. Startup times are noticeably faster, and precompilation works better.
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### Author:  [@martenlienen](https://discourse.julialang.org/u/martenlienen)
#### Post date: [October 7, 2020, 7:42am UTC](https://discourse.julialang.org/t/compiling-a-project-specific-sysimage/47902/3 "2020-10-07T07:42:49Z")
I read the blog post on invalidations and can’t wait for the release of 1.6! Do you think custom sysimages will still be useful or required?