diff --git a/scripts/build-all.ts b/scripts/build-all.ts
index 1c7404ef..d7ad09e2 100755
--- a/scripts/build-all.ts
+++ b/scripts/build-all.ts
@@ -13,7 +13,6 @@ args:
 ---*/
 
 import usePantry from "hooks/usePantry.ts"
-import hydrate from "prefab/hydrate.ts"
 import build from "prefab/build.ts"
 import doInstall from "prefab/install.ts"
 import { lvl1 as link } from "prefab/link.ts"
@@ -95,16 +94,15 @@ async function buildIfNeeded({ project, install }: BuildOptions) {
     console.verbose({ building: project })
   }
 
-  const deps = await pantry.getDeps({ pkg, wbuild: true })
-  const graph = await hydrate(deps)
+  const deps = await pantry.getDeps(pkg)
 
-  for (const dep of graph) {
+  for (const dep of [...deps.build, ...deps.runtime]) {
     await buildIfNeeded({ project: dep, install: true })
   }
 
   await prepare(pkg)
   try {
-    const path = await build({ pkg, deps: graph })
+    const path = await build({ pkg, deps })
     await link({ path, pkg })
     results.built.push(`${pkg.project}-${pkg.version.version}`)
   } catch (error) {
diff --git a/scripts/build.ts b/scripts/build.ts
index 660e694a..bda7138e 100755
--- a/scripts/build.ts
+++ b/scripts/build.ts
@@ -12,7 +12,6 @@ args:
   - --import-map={{ srcroot }}/import-map.json
 ---*/
 
-import hydrate from "prefab/hydrate.ts"
 import build from "prefab/build.ts"
 import { lvl1 as link } from "prefab/link.ts"
 import usePantry from "hooks/usePantry.ts"
@@ -39,7 +38,7 @@ for (const req of args[0].map(parsePackageRequirement)) {
   if (!version) throw "no-version-found"
   const pkg = { project: req.project, version }
   console.debug(pkg)
-  const deps = await pantry.getDeps({ pkg, wbuild: true })
+  const deps = await pantry.getDeps(pkg)
 
   console.debug({ deps })
 
diff --git a/src/hooks/usePantry.ts b/src/hooks/usePantry.ts
index b8775eea..390b6429 100644
--- a/src/hooks/usePantry.ts
+++ b/src/hooks/usePantry.ts
@@ -5,16 +5,11 @@ import useCellar from "hooks/useCellar.ts"
 import usePlatform from "hooks/usePlatform.ts"
 
 
-interface GetDepsOptions {
-  pkg: Package | PackageRequirement
-  wbuild?: boolean
-}
-
 interface Response {
   getDistributable(rq: Package): Promise<{ url: string, stripComponents?: number }>
   /// returns sorted versions
   getVersions(rq: PackageRequirement | Package): Promise<SemVer[]>
-  getDeps(opts: GetDepsOptions): Promise<PackageRequirement[]>
+  getDeps(pkg: Package | PackageRequirement): Promise<{ runtime: PackageRequirement[], build: PackageRequirement[] }>
   getBuildScript(pkg: Package): Promise<string>
   update(): Promise<void>
   getProvides(rq: PackageRequirement | Package): Promise<string[]>
@@ -74,9 +69,12 @@ export default function usePantry(): Response {
     }
   }
 
-  const getDeps = async ({pkg, wbuild}: GetDepsOptions) => {
+  const getDeps = async (pkg: Package | PackageRequirement) => {
     const yml =  await entry(pkg).yml()
-    return go(yml.dependencies).concat(go(wbuild && yml.build?.dependencies))
+    return {
+      runtime: go(yml.dependencies),
+      build: go(yml.build?.dependencies)
+    }
     // deno-lint-ignore no-explicit-any
     function go(node: any) {
       if (!node) return []
diff --git a/src/prefab/build.ts b/src/prefab/build.ts
index ce3e1636..c338571e 100644
--- a/src/prefab/build.ts
+++ b/src/prefab/build.ts
@@ -1,4 +1,4 @@
-import { Path, Package, PackageRequirement } from "types"
+import { Path, Package, PackageRequirement, semver } from "types"
 import usePantry from "hooks/usePantry.ts"
 import useCellar from "hooks/useCellar.ts"
 import useShellEnv from "hooks/useShellEnv.ts"
@@ -7,14 +7,17 @@ import usePlatform from "hooks/usePlatform.ts";
 
 interface Options {
   pkg: Package
-  deps: PackageRequirement[]
+  deps: {
+    build: PackageRequirement[]
+    runtime: PackageRequirement[]
+  }
 }
 
 export default async function build({ pkg, deps }: Options): Promise<Path> {
   const pantry = usePantry()
   const dst = useCellar().mkpath(pkg)
   const src = dst.join("src")
-  const env = await useShellEnv(deps)
+  const env = await useShellEnv([...deps.build, ...deps.runtime])
   const sh = await pantry.getBuildScript(pkg)
   const { platform } = usePlatform()
 
@@ -40,6 +43,10 @@ export default async function build({ pkg, deps }: Options): Promise<Path> {
   }).chmod(0o500)
 
   await run({ cmd })
+  await fix(dst, [
+    ...deps.runtime,
+    {project: pkg.project, constraint: new semver.Range(`=${pkg.version}`)}
+  ] )
 
   return dst
 }
@@ -52,3 +59,42 @@ function expand(env: Record<string, string[]>) {
   }
   return rv
 }
+
+async function* exefiles(prefix: Path) {
+  for (const basename of ["bin", "lib"]) { //TODO the rest
+    const d = prefix.join(basename).isDirectory()
+    if (!d) continue
+    for await (const [exename] of d.ls()) {
+      if (exename.isExecutableFile()) yield exename
+    }
+  }
+}
+
+/// fix rpaths or install names for executables and dynamic libraries
+async function fix(prefix: Path, pkgs: PackageRequirement[]) {
+  if (usePlatform().platform != 'linux') return
+  // ^^ TODO we need to do this on mac too
+
+  for await (const exename of exefiles(prefix)) {
+    await setRpath(exename, pkgs)
+  }
+}
+
+//TODO this is not resilient to upgrades (obv)
+async function setRpath(exename: Path, pkgs: PackageRequirement[]) {
+  const cellar = useCellar()
+  const rpath = (await Promise.all(pkgs.map(pkg => prefix(pkg)))).join(":")
+
+  try {
+    await run({
+      cmd: ["patchelf", "--set-rpath", rpath, exename]
+    })
+  } catch (e) {
+    console.warn(e)
+    //FIXME we skip all errors as we are not checking if files are executables rather than eg. scripts
+  }
+
+  async function prefix(pkg: PackageRequirement) {
+    return (await cellar.resolve(pkg)).path.join("lib").string
+  }
+}
diff --git a/src/prefab/hydrate.ts b/src/prefab/hydrate.ts
index 0ebdadcb..0d0722a8 100644
--- a/src/prefab/hydrate.ts
+++ b/src/prefab/hydrate.ts
@@ -12,7 +12,7 @@ export default async function hydrate(reqs: PackageRequirement[]): Promise<Packa
   while (stack.length > 0) {
     const curr = stack.shift()!
 
-    for (const dep of await pantry.getDeps({ pkg: curr })) {
+    for (const dep of (await pantry.getDeps(curr)).runtime) {
       if (dep.project in set) {
         const intersection = semver_intersection(set[dep.project]!, dep.constraint)
         // ^^ throws if no intersection possible