D compiler installation ldc failed

[Martin Michel]

Hello again,

today I wanted to install the LLVM-based compiler `ldc` for the D programming 
language (along with its package management system `dub`).
This failed grossly:

```
$ guix install ldc dub
The following packages will be installed:
   dub 1.7.2
   ldc 1.27.1

substitute: updating substitutes from 'https://ci.guix.gnu.org'... 100.0%
substitute: updating substitutes from 'https://bordeaux.guix.gnu.org'... 100.0%
The following derivation will be built:
  /gnu/store/gnc9jbwxwbplvpygb276p5fkp3q1l7v2-dub-1.7.2.drv

8.2 MB will be downloaded
 ldc-1.27.1  7.8MiB                           3.2MiB/s 00:02 
[##################] 100.0%
building /gnu/store/gnc9jbwxwbplvpygb276p5fkp3q1l7v2-dub-1.7.2.drv...
/ 'build' phasebuilder for 
`/gnu/store/gnc9jbwxwbplvpygb276p5fkp3q1l7v2-dub-1.7.2.drv' failed with exit 
code 1
build of /gnu/store/gnc9jbwxwbplvpygb276p5fkp3q1l7v2-dub-1.7.2.drv failed
View build log at 
'/var/log/guix/drvs/gn/c9jbwxwbplvpygb276p5fkp3q1l7v2-dub-1.7.2.drv.gz'.
guix install: error: build of 
`/gnu/store/gnc9jbwxwbplvpygb276p5fkp3q1l7v2-dub-1.7.2.drv' failed
```

Unfortunately the tail of the log does not help me:

```
--- cut off many lines ---
starting phase `build'
./build.sh: line 45: git: command not found
Could not determine a version with git.
Using existing version file.
Running ldmd2...
source/dub/semver.d(107): Deprecation: Usage of the `body` keyword is 
deprecated. Use `do` instead.
source/dub/internal/sdlang/parser.d(121): Deprecation: module std.variant is 
not accessible here, perhaps add 'static import std.variant;'
source/dub/internal/sdlang/parser.d(121): Deprecation: module std.variant is 
not accessible here, perhaps add 'static import std.variant;'
Serializing composite type BuildRequirements which has no serializable fields
Serializing composite type BuildOptions which has no serializable fields
source/dub/internal/vibecompat/data/json.d(2111): Error: template instance 
`enforceEx!JSONException` template `enforceEx` is not defined, did you mean 
enforce(E : Throwable = Exception) if (is(typeof(new E("", string.init, 
size_t.init)) : Throwable) || is(typeof(new E(string.init, size_t.init)) : 
Throwable))?
source/dub/internal/vibecompat/data/json.d(838): Error: template instance 
`dub.internal.vibecompat.data.json.enforceJson!("source/dub/internal/vibecompat/data/json.d",
 838LU)` error instantiating
source/dub/internal/vibecompat/data/json.d(221):        instantiated from here: 
`checkType!(Json[string])`
source/dub/dependency.d(309):        instantiated from here: 
`opBinaryRight!"in"`
source/dub/internal/vibecompat/data/json.d(2111): Error: template instance 
`enforceEx!JSONException` template `enforceEx` is not defined, did you mean 
enforce(E : Throwable = Exception) if (is(typeof(new E("", string.init, 
size_t.init)) : Throwable) || is(typeof(new E(string.init, size_t.init)) : 
Throwable))?
source/dub/internal/vibecompat/data/json.d(839): Error: template instance 
`dub.internal.vibecompat.data.json.enforceJson!("source/dub/internal/vibecompat/data/json.d",
 839LU)` error instantiating
source/dub/internal/vibecompat/data/json.d(221):        instantiated from here: 
`checkType!(Json[string])`
source/dub/dependency.d(309):        instantiated from here: 
`opBinaryRight!"in"`
source/dub/internal/vibecompat/data/json.d(403): Error: template instance 
`dub.internal.vibecompat.data.json.Json.checkType!string` error instantiating
source/dub/dependency.d(314):        instantiated from here: `get!string`
source/dub/internal/vibecompat/data/json.d(403): Error: template instance 
`dub.internal.vibecompat.data.json.Json.checkType!bool` error instantiating
source/dub/internal/vibecompat/data/json.d(399):        instantiated from here: 
`get!bool`
source/dub/internal/vibecompat/data/json.d(1744):        instantiated from 
here: `opCast!bool`
source/dub/recipe/io.d(158):        instantiated from here: 
`writeJsonString!(LockingTextWriter, true)`
source/dub/dub.d(1102):        instantiated from here: 
`serializePackageRecipe!(LockingTextWriter)`
source/dub/internal/vibecompat/data/json.d(403): Error: template instance 
`dub.internal.vibecompat.data.json.Json.checkType!long` error instantiating
error: in phase 'build': uncaught exception:
%exception #<&invoke-error program: "./build.sh" arguments: () exit-status: 1 
term-signal: #f stop-signal: #f>
phase `build' failed after 16.0 seconds
command "./build.sh" failed with status 1
```

What to do in such cases? Any help is welcome!

Thanks in advance & kind regards,
Martin