[BUG] and/or inaccurate documentation in Attachments Tutorial, with respect to attach()

[david-a-hillman]

Describe the bug
Sample code from the Attachments tutorial at the following link generates errors, and does not work as documented.

https://github.com/BelfrySCAD/BOSL2/wiki/Tutorial-Attachment-Attach

Behavior is the same in both versions 2101.01 and 2026.03.22 (git d0c22917)

Code To Reproduce Bug

Example from the aforementioned URL follows, exactly as published.

include <BOSL2/std.scad>
module thing(){
  color_this("orange")
    prismoid([8,8],[6,6],shift=-[1,1],h=8) {
      attach(TOP,BOT) anchor_arrow(color=[0,1,0],s=12);
      attach(FWD,BOT) anchor_arrow(s=12);     
    }
}
prismoid([50,50],[35,35],h=25,anchor=BOT){
  attach(TOP,BOT,align=FRONT) thing();
  attach(RIGHT,BOT,align=BOT) thing();    
  attach(RIGHT,BACK,align=FRONT) thing();
  attach(FRONT,BACK,align=BOT,spin=45) thing();
  attach(TOP,RIGHT,align=RIGHT,spin=90) thing();
}

Expected behavior
Expected behavior is documented in the aforementioned tutorial, along with a screenshot of the expected behavior, which has been reproduced below. Specifically, attach() is documented to provide an "align" parameter that does not appear to be implemented in the versions that I tested.

Observed behavior

Compiling design (CSG Tree generation)...
[WARNING: variable align not specified as parameter in file BOSL2, line 10](filename redacted)
[WARNING: variable align not specified as parameter in file BOSL2, line 11](filename redacted)
[WARNING: variable align not specified as parameter in file BOSL2, line 12](filename redacted)
[WARNING: variable align not specified as parameter in file BOSL2, line 13](filename redacted)
[WARNING: variable spin not specified as parameter in file BOSL2, line 13](filename redacted)
[WARNING: variable align not specified as parameter in file BOSL2, line 14](filename redacted)
[WARNING: variable spin not specified as parameter in file BOSL2, line 14](filename redacted)
Compiling design (CSG Products generation)...
Geometries in cache: 13
Geometry cache size in bytes: 24496
CGAL Polyhedrons in cache: 0
CGAL cache size in bytes: 0
Compiling design (CSG Products normalization)...
Normalized tree has 46 elements!
Compile and preview finished.
Total rendering time: 0:00:00.489

See also screenshot below.

Screenshots
Expected behavior, per the tutorial:

Observed behavior in OpenSCAD v 2101.01:

Observed behavior in OpenSCAD v 2026.03.22:

Additional context

• OpenSCAD Version: 2101.01 and 2026.03.22 (git d0c22917)
• Other libraries used: none

[RAMilewski]

I think you're probably using a old version of BOSL2. Update to v2.0.730. Works for me:

[david-a-hillman]

I think you're probably using a old version of BOSL2. Update to v2.0.730. Works for me:

Perhaps, but there's nothing in the changelog for the versions following the one that I have, which seems to address this area.

[adrianVmariano]

First of all, the tutorials and documentation figures and diagrams are produced automatically by running the current BOSL2 version. It is therefore impossible that they are "incorrect". If your version doesn't reproduce those diagrams then you need to update.

The align option to attach() was added a long time ago---not sure exactly how long but two years? Maybe longer. If you think you're running a newer version use the version() command to check. Maybe you aren't including the version you think.

[adrianVmariano]

The correct full command to display the BOSL2 version is echo(bosl_version_str());.