How to determine location of scripts/executables, and set directory where scripts/executable is run

[pcarbo]

Suppose I do

cd ~
dsc /project/mstephens/gaow/dsc-fun/benchmark.dsc

Where does DSC look for the scripts? From which directory are the scripts run?

For guidance it might be helpful to look at argument knit_root_dir in rmarkdown::render because it has to deal with similar issues; see help(render) in R.

[gaow]

First let's discuss the expected behavior:

1. working dir default: should it be current dir or the dir where one keeps DSC file? -- makes sense to use current dir.
2. relative paths in DSC section: relative to working dir or to where DSC files are? -- makes sense to use folder where DSC file is at.

Note that for 1, I will always convert to use absolute path. But for 2 i'll have to keep it relative path because it will impact how scripts look like, and therefore trigger unnecessary reruns otherwise.

Once we are clear on this, the rest is just coding. As you can see it is more complex due to pipeline behavior, that we cannot just expand everything to use absolute paths. I'll find one peaceful weekend morning to port all path related strings in DSC code to use a formal Python path class (a variant of pathlib in Python 3.6 from SoS) that will resolve path related issues once and for all.

[pcarbo]

@gaow I agree it is important to come up to a consensus on this.

[gaow]

So @pcarbo you agree with my proposed behavior of 1 & 2 above?

[pcarbo]

@gaow Here is a problem with the proposal for 1: relative paths inside the code would only work correctly if the dsc command were run in a prespecified location, which would be very restrictive. On the other hand, if it were with respect to the DSC file or the source code, the dsc command could work anywhere.

[gaow]

Yes you are right. Okey now that we are clear about it i'll find some time to make changes to all path strings in the code.

[pcarbo]

When reporting relative paths we will also have to be careful to explain what these paths are relative to. (Or just report absolute paths.)