---
sidebar_label: FAQ
---
# FAQ
## Registry not found
```
error: registry not found
```
**Solution:** Make sure `~/.dcr/config.toml` exists:
```toml
[registry.default]
url = "https://index.dcr.pm"
priority = 1
```
And check `DCR_INDEX_PATH`:
```bash
echo $DCR_INDEX_PATH
```
## Compiler not found
```
error: compiler not found
```
**Solution:** Ensure a compiler is installed and available in PATH.
```bash
which gcc
which clang
```
Or specify explicitly via `[toolchain]` in `dcr.toml`.
## Ctrl+C during build
DCR handles SIGINT: interrupts the current compilation and exits with non-zero code.
## How to create a library?
See [Library Recipe](/docs/recipes/library-project).
## How to cross-compile to Windows?
See [Cross-Compile Recipe](/docs/recipes/cross-to-windows).
## How to create a multi-package project?
See [Workspace Recipe](/docs/recipes/multi-package-workspace).
## Bootloader / pure NASM OS image
Use `kind = "flat-bin"` (NASM `-f bin`) and optional `[archive]` for a FAT disk image.
See [OS-dev recipe](/docs/recipes/os-flat-bin-archive).
## Lock file
`dcr.lock` is created during builds (`dcr build`) when registry dependencies are present. To force an update — delete `dcr.lock` and run `dcr build`.